If you don't also accept my draw offer when I have a clearly lost position, you lose too
If you don’t accept at least one rematch after you win, then you lose.

I don't think acceptance of rematch decides the match tho, it's simply just a rematch and what decides the winner and the loser is the match's end

What if any person won match and then got strong natural call?
I think this comment is written after frustration of losing to many matches and then opponent not accepting rematch request.
I completely agree with this. It's so frustrating to not receive a rematch. Everytime I win, I wait to see if my opponent offers one, if I don't offer it myself. And if I have any majority reason that prevent me from playing again, I explain it.
Why to explain anything? My opponent didn’t explain why he asks a rematch, he just clicked the button, I also just click the button - Decline.
We all know the reason anyone asks for a rematch. They want to try again. It's called sport spirit. Declining a rematch request, however, at least after the very first match and having won, is kind of rude and not very sporty. If you see the rematch challenge and you have a reason that prevents you from playing again, the best would be to excuse yourself rather than ignoring your opponent. Then it's understandable. Anyone with a sport spirit will be willing to play with any opponent a second time, if not now, some other day.
I also have a very obvious reason to decline: I don't want to try again right now, no need to explain it in words, a button click will suffice.
There is nothing rude or unsportsmanlike in declining a rematch request. In competitive chess rematches simply don't exist. Just try to play a rated OTB game in a tourney, ask for a rematch and see the reaction.
I'm pretty sure every grand master has played most of their opponents more than once. A lot of tournaments are the best of 3 or 5, and there's always the next tournament. If you don't feel like trying again right now, that's fine, but it's still rude not to at least excuse yourself and ignore your opponent when they're sending you a request. The best you can do is, if not play the rematch then, send a friend request and play it later.
I have nothing against playing same opponent again when the seek algorithm will pair us up in the future.
Please give me an example of a tournament where it's "the best of 3 or 5". I don't know any. In vast majority of OTB tournaments you play an opponent just once. In 10 years of competitive play as a club member I have never played same player more than once in the same competition. And even if more than one game is played it's predefined by the format of the competition. Format here is simple: one game. Rematch button was added as convenient mean to play more games with same opponent when both want it. Then people like use started inventing "rules" around it.
I have nothing to excuse myself for as I do nothing wrong. We agreed to play one game, that's it. If my opponent doesn't write me why he wants to play again I don't see any need to write him why I don't want it.
For what I've heard there are tournaments in which players play multiple games. If not in chess, in most sports. And even if there aren't, as I said, there's always the next tournament. Saying that you would only play with some opponent if you happen to be forced, like if you're lucky enough to be paired by the algorithm once again, is pretty much the same as not being willing to play with that opponent again, as you're not doing anything form your part to allow that rematch to happen. You can argue that you have the right to leave not giving any excuse, since a rematch is an agreement of both parts; and you'd be right; but it's still ignoring a person, it's still rude and it's still unsportmanlike.
I am glad you agree that there are no rematches (in the sense "let's try again") in competitive chess. It might happen that a GM will play same opponent in another tournament. It's no different for me - it might happen I will play same opponent if paired up by seek algorithm. It's not about willing or not to play him again, I just don't care whom I will play next time, I don't have any preference for him vs some other random anonymous player from the internet. What I certainly don't want is to play him again right now. And I don't feel any need to provide an excuse.
I am not totally "ignoring a person", I clicked Decline button. He is not entitled to anything more just because we've played a game. If this is rude, than he is just as rude by clicking Rematch without explaining his motifs. He could say that he liked my style, or that he wants to play 3 games to see who is better, or that his coach told him to always try to rematch. Just to say anything to be polite. But he silently clicked the button, and so did I.
What is unsportmanlike is not decided by you, it's a question of a consensus. If you check all the answers in this and similar threads you will see that vast majority of players think like me.

I don't know why people feel entitled to rematches and resignation from the opponent
Honestly I don't get it too but these type of threads are hilarious

I don't know why people feel entitled to rematches and resignation from the opponent
Honestly I don't get it too but these type of threads are hilarious
Tru

In other words, instead of accepting that you lost a game you want to pretend you're somehow the winner.
Everyone loses. Sometimes the person we lose to isn't as good as we are, but we lose anyway. Instead of insisting on a rematch just accept it and move on.
Agreed.

I completely agree with this. It's so frustrating to not receive a rematch. Everytime I win, I wait to see if my opponent offers one, if I don't offer it myself. And if I have any majority reason that prevent me from playing again, I explain it.
Why to explain anything? My opponent didn’t explain why he asks a rematch, he just clicked the button, I also just click the button - Decline.
We all know the reason anyone asks for a rematch. They want to try again. It's called sport spirit. Declining a rematch request, however, at least after the very first match and having won, is kind of rude and not very sporty. If you see the rematch challenge and you have a reason that prevents you from playing again, the best would be to excuse yourself rather than ignoring your opponent. Then it's understandable. Anyone with a sport spirit will be willing to play with any opponent a second time, if not now, some other day.
I also have a very obvious reason to decline: I don't want to try again right now, no need to explain it in words, a button click will suffice.
There is nothing rude or unsportsmanlike in declining a rematch request. In competitive chess rematches simply don't exist. Just try to play a rated OTB game in a tourney, ask for a rematch and see the reaction.
I'm pretty sure every grand master has played most of their opponents more than once. A lot of tournaments are the best of 3 or 5, and there's always the next tournament. If you don't feel like trying again right now, that's fine, but it's still rude not to at least excuse yourself and ignore your opponent when they're sending you a request. The best you can do is, if not play the rematch then, send a friend request and play it later.
I have nothing against playing same opponent again when the seek algorithm will pair us up in the future.
Please give me an example of a tournament where it's "the best of 3 or 5". I don't know any. In vast majority of OTB tournaments you play an opponent just once. In 10 years of competitive play as a club member I have never played same player more than once in the same competition. And even if more than one game is played it's predefined by the format of the competition. Format here is simple: one game. Rematch button was added as convenient mean to play more games with same opponent when both want it. Then people like use started inventing "rules" around it.
I have nothing to excuse myself for as I do nothing wrong. We agreed to play one game, that's it. If my opponent doesn't write me why he wants to play again I don't see any need to write him why I don't want it.
For what I've heard there are tournaments in which players play multiple games. If not in chess, in most sports. And even if there aren't, as I said, there's always the next tournament. Saying that you would only play with some opponent if you happen to be forced, like if you're lucky enough to be paired by the algorithm once again, is pretty much the same as not being willing to play with that opponent again, as you're not doing anything form your part to allow that rematch to happen. You can argue that you have the right to leave not giving any excuse, since a rematch is an agreement of both parts; and you'd be right; but it's still ignoring a person, it's still rude and it's still unsportmanlike.
I am glad you agree that there are no rematches (in the sense "let's try again") in competitive chess. It might happen that a GM will play same opponent in another tournament. It's no different for me - it might happen I will play same opponent if paired up by seek algorithm. It's not about willing or not to play him again, I just don't care whom I will play next time, I don't have any preference for him vs some other random anonymous player from the internet. What I certainly don't want is to play him again right now. And I don't feel any need to provide an excuse.
I am not totally "ignoring a person", I clicked Decline button. He is not entitled to anything more just because we've played a game. If this is rude, than he is just as rude by clicking Rematch without explaining his motifs. He could say that he liked my style, or that he wants to play 3 games to see who is better, or that his coach told him to always try to rematch. Just to say anything to be polite. But he silently clicked the button, and so did I.
What is unsportmanlike is not decided by you, it's a question of a consensus. If you check all the answers in this and similar threads you will see that vast majority of players think like me.
Again if you don't want to play again right now, send a friend request and have the rematch later. And yes, you're pretty much ignoring your opponent even if you're clicking "decline". There's no difference in what the opponent sees if you don't say anything.
I don't think you're understanding why I'm saying it's rude if you're trying to say offering the rematch is just as rude with no basis. With all respect, that just sounds like a "No, you" argument. The reason I say it's rude is because the opponent is sending you a message and you're offering nothing in return by either declining it or ignoring it, which have the same effect. The least you can do is say something.
I'm not saying it's unsportsmanlike because I claim to define it. I don't know which part of my message lead you to believe I'm claiming to define it. I think it would make a lot more sense to explain why exactly you think this is not if that's your purpose, rather than just saying not just because I say so. But I digress. The reason I say it's unsportsmanlike is because you're basically making sure not to play with that opponent again, unless you happen to be forced by chance. It would be the same if you just wait to see if you happened to be paired up in the next tournament and denying any friendly match.

I completely agree with this. It's so frustrating to not receive a rematch. Everytime I win, I wait to see if my opponent offers one, if I don't offer it myself. And if I have any majority reason that prevent me from playing again, I explain it.
Why to explain anything? My opponent didn’t explain why he asks a rematch, he just clicked the button, I also just click the button - Decline.
We all know the reason anyone asks for a rematch. They want to try again. It's called sport spirit. Declining a rematch request, however, at least after the very first match and having won, is kind of rude and not very sporty. If you see the rematch challenge and you have a reason that prevents you from playing again, the best would be to excuse yourself rather than ignoring your opponent. Then it's understandable. Anyone with a sport spirit will be willing to play with any opponent a second time, if not now, some other day.
I also have a very obvious reason to decline: I don't want to try again right now, no need to explain it in words, a button click will suffice.
There is nothing rude or unsportsmanlike in declining a rematch request. In competitive chess rematches simply don't exist. Just try to play a rated OTB game in a tourney, ask for a rematch and see the reaction.
I'm pretty sure every grand master has played most of their opponents more than once. A lot of tournaments are the best of 3 or 5, and there's always the next tournament. If you don't feel like trying again right now, that's fine, but it's still rude not to at least excuse yourself and ignore your opponent when they're sending you a request. The best you can do is, if not play the rematch then, send a friend request and play it later.
I have nothing against playing same opponent again when the seek algorithm will pair us up in the future.
Please give me an example of a tournament where it's "the best of 3 or 5". I don't know any. In vast majority of OTB tournaments you play an opponent just once. In 10 years of competitive play as a club member I have never played same player more than once in the same competition. And even if more than one game is played it's predefined by the format of the competition. Format here is simple: one game. Rematch button was added as convenient mean to play more games with same opponent when both want it. Then people like use started inventing "rules" around it.
I have nothing to excuse myself for as I do nothing wrong. We agreed to play one game, that's it. If my opponent doesn't write me why he wants to play again I don't see any need to write him why I don't want it.
For what I've heard there are tournaments in which players play multiple games. If not in chess, in most sports. And even if there aren't, as I said, there's always the next tournament. Saying that you would only play with some opponent if you happen to be forced, like if you're lucky enough to be paired by the algorithm once again, is pretty much the same as not being willing to play with that opponent again, as you're not doing anything form your part to allow that rematch to happen. You can argue that you have the right to leave not giving any excuse, since a rematch is an agreement of both parts; and you'd be right; but it's still ignoring a person, it's still rude and it's still unsportmanlike.
I am glad you agree that there are no rematches (in the sense "let's try again") in competitive chess. It might happen that a GM will play same opponent in another tournament. It's no different for me - it might happen I will play same opponent if paired up by seek algorithm. It's not about willing or not to play him again, I just don't care whom I will play next time, I don't have any preference for him vs some other random anonymous player from the internet. What I certainly don't want is to play him again right now. And I don't feel any need to provide an excuse.
I am not totally "ignoring a person", I clicked Decline button. He is not entitled to anything more just because we've played a game. If this is rude, than he is just as rude by clicking Rematch without explaining his motifs. He could say that he liked my style, or that he wants to play 3 games to see who is better, or that his coach told him to always try to rematch. Just to say anything to be polite. But he silently clicked the button, and so did I.
What is unsportmanlike is not decided by you, it's a question of a consensus. If you check all the answers in this and similar threads you will see that vast majority of players think like me.
Again if you don't want to play again right now, send a friend request and have the rematch later. And yes, you're pretty much ignoring your opponent even if you're clicking "decline". There's no difference in what the opponent sees if you don't say anything.
I don't think you're understanding why I'm saying it's rude if you're trying to say offering the rematch is just as rude with no basis. With all respect, that just sounds like a "No, you" argument. The reason I say it's rude is because the opponent is sending you a message and you're offering nothing in return by either declining it or ignoring it, which have the same effect. The least you can do is say something.
I'm not saying it's unsportsmanlike because I claim to define it. I don't know which part of my message lead you to believe I'm claiming to define it. I think it would make a lot more sense to explain why exactly you think this is not if that's your purpose, rather than just saying not just because I say so. But I digress. The reason I say it's unsportsmanlike is because you're basically making sure not to play with that opponent again, unless you happen to be forced by chance. It would be the same if you just wait to see if you happened to be paired up in the next tournament and denying any friendly match.
I don't want to be friends with some anonymous player just because we played a game. He can equally send me a friend request if he wants to, I will probably accept.
If you consider clicking Rematch as a message, then clicking Decline is a message as well. It's totally symmetric. I don't have to say anything because he didn't say anything neither.
I don't see why I have more obligations (like sending a friend request or a text message) just because I won the game.
It's a consensus in online chess that declining a rematch is perfectly fine regarding the sportsmanship and no excuses should be made. You claim that it's unsportsmanlike looks your own invention and your own definition of a sportsmanship. If it's not then please share with us where you took it from.
"Sportsmanship: behaviour in sport that is fair and shows respect to the other players" (Cambridge dictionary). I follow this code of conduct 100%: I don't say anything abusive in chat, don't ask my opponent to resign in hopeless position, don't celebrate my victory in any inappropriate way. You show bad sportsmanship by not respecting my decision not to play another game. You are a rude person blaming others when they do nothing wrong.
I am making sure not to play with that opponent again right now, you see the difference? Not never, just not right now.

I completely agree with this. It's so frustrating to not receive a rematch. Everytime I win, I wait to see if my opponent offers one, if I don't offer it myself. And if I have any majority reason that prevent me from playing again, I explain it.
Why to explain anything? My opponent didn’t explain why he asks a rematch, he just clicked the button, I also just click the button - Decline.
We all know the reason anyone asks for a rematch. They want to try again. It's called sport spirit. Declining a rematch request, however, at least after the very first match and having won, is kind of rude and not very sporty. If you see the rematch challenge and you have a reason that prevents you from playing again, the best would be to excuse yourself rather than ignoring your opponent. Then it's understandable. Anyone with a sport spirit will be willing to play with any opponent a second time, if not now, some other day.
I also have a very obvious reason to decline: I don't want to try again right now, no need to explain it in words, a button click will suffice.
There is nothing rude or unsportsmanlike in declining a rematch request. In competitive chess rematches simply don't exist. Just try to play a rated OTB game in a tourney, ask for a rematch and see the reaction.
I'm pretty sure every grand master has played most of their opponents more than once. A lot of tournaments are the best of 3 or 5, and there's always the next tournament. If you don't feel like trying again right now, that's fine, but it's still rude not to at least excuse yourself and ignore your opponent when they're sending you a request. The best you can do is, if not play the rematch then, send a friend request and play it later.
I have nothing against playing same opponent again when the seek algorithm will pair us up in the future.
Please give me an example of a tournament where it's "the best of 3 or 5". I don't know any. In vast majority of OTB tournaments you play an opponent just once. In 10 years of competitive play as a club member I have never played same player more than once in the same competition. And even if more than one game is played it's predefined by the format of the competition. Format here is simple: one game. Rematch button was added as convenient mean to play more games with same opponent when both want it. Then people like use started inventing "rules" around it.
I have nothing to excuse myself for as I do nothing wrong. We agreed to play one game, that's it. If my opponent doesn't write me why he wants to play again I don't see any need to write him why I don't want it.
For what I've heard there are tournaments in which players play multiple games. If not in chess, in most sports. And even if there aren't, as I said, there's always the next tournament. Saying that you would only play with some opponent if you happen to be forced, like if you're lucky enough to be paired by the algorithm once again, is pretty much the same as not being willing to play with that opponent again, as you're not doing anything form your part to allow that rematch to happen. You can argue that you have the right to leave not giving any excuse, since a rematch is an agreement of both parts; and you'd be right; but it's still ignoring a person, it's still rude and it's still unsportmanlike.
I am glad you agree that there are no rematches (in the sense "let's try again") in competitive chess. It might happen that a GM will play same opponent in another tournament. It's no different for me - it might happen I will play same opponent if paired up by seek algorithm. It's not about willing or not to play him again, I just don't care whom I will play next time, I don't have any preference for him vs some other random anonymous player from the internet. What I certainly don't want is to play him again right now. And I don't feel any need to provide an excuse.
I am not totally "ignoring a person", I clicked Decline button. He is not entitled to anything more just because we've played a game. If this is rude, than he is just as rude by clicking Rematch without explaining his motifs. He could say that he liked my style, or that he wants to play 3 games to see who is better, or that his coach told him to always try to rematch. Just to say anything to be polite. But he silently clicked the button, and so did I.
What is unsportmanlike is not decided by you, it's a question of a consensus. If you check all the answers in this and similar threads you will see that vast majority of players think like me.
Again if you don't want to play again right now, send a friend request and have the rematch later. And yes, you're pretty much ignoring your opponent even if you're clicking "decline". There's no difference in what the opponent sees if you don't say anything.
I don't think you're understanding why I'm saying it's rude if you're trying to say offering the rematch is just as rude with no basis. With all respect, that just sounds like a "No, you" argument. The reason I say it's rude is because the opponent is sending you a message and you're offering nothing in return by either declining it or ignoring it, which have the same effect. The least you can do is say something.
I'm not saying it's unsportsmanlike because I claim to define it. I don't know which part of my message lead you to believe I'm claiming to define it. I think it would make a lot more sense to explain why exactly you think this is not if that's your purpose, rather than just saying not just because I say so. But I digress. The reason I say it's unsportsmanlike is because you're basically making sure not to play with that opponent again, unless you happen to be forced by chance. It would be the same if you just wait to see if you happened to be paired up in the next tournament and denying any friendly match.
I don't want to be friends with some anonymous player just because we played a game. He can equally send me a friend request if he wants to, I will probably accept.
If you consider clicking Rematch as a message, then clicking Decline is a message as well. It's totally symmetric. I don't have to say anything because he didn't say anything neither.
I don't see why I have more obligations (like sending a friend request or a text message) just because I won the game.
It's a consensus in online chess that declining a rematch is perfectly fine regarding the sportsmanship and no excuses should be made. You claim that it's unsportsmanlike looks your own invention and your own definition of a sportsmanship. If it's not then please share with us where you took it from.
"Sportsmanship: behaviour in sport that is fair and shows respect to the other players" (Cambridge dictionary). I follow this code of conduct 100%: I don't say anything abusive in chat, don't ask my opponent to resign in hopeless position, don't celebrate my victory in any inappropriate way. You show bad sportsmanship by not respecting my decision not to play another game. You are a rude person blaming others when they do nothing wrong.
I am making sure not to play with that opponent again right now, you see the difference? Not never, just not right now.
Declining the rematch is not sending a message back, as the opponent doesn't receive any kind of notification whatsoever. And even if they did, it's still just like saying "No" and leaving with no further explanation. Yeah, you don't have any obligation to accept it, but again, declining it, specially after wining the first game, and specially without saying anything, is still not very nice, even if it's not against the rules.
The reason I say it's unsportsmanlike is not because you're breaking the rules, being offensive or anything. Rather, I mean it shows a lack of competitive spirit, having a person in front of you that you know is willing to have another game and putting no effort (except maybe for not blocking them) in allowing that rematch to at least happen another day. If what you say about "not never, just not right now" is true, then that's ok: send a friend request or at least a message.

I suggest to chess.com they make a choice of TWO Game match. It's automatic then those who are matched must play 2 games. Aborting the 2nd game is loss and loss of rating points.
Playing a serious game takes a lot out of me, I invest a lot of mental energy. At the end of the game I am experiencing a sudden release of adrenaline. I feel exhausted and jazzed at the same time. If I played another game immediately I would almost certainly lose.
I completely agree with this. It's so frustrating to not receive a rematch. Everytime I win, I wait to see if my opponent offers one, if I don't offer it myself. And if I have any majority reason that prevent me from playing again, I explain it.
Why to explain anything? My opponent didn’t explain why he asks a rematch, he just clicked the button, I also just click the button - Decline.
We all know the reason anyone asks for a rematch. They want to try again. It's called sport spirit. Declining a rematch request, however, at least after the very first match and having won, is kind of rude and not very sporty. If you see the rematch challenge and you have a reason that prevents you from playing again, the best would be to excuse yourself rather than ignoring your opponent. Then it's understandable. Anyone with a sport spirit will be willing to play with any opponent a second time, if not now, some other day.
I also have a very obvious reason to decline: I don't want to try again right now, no need to explain it in words, a button click will suffice.
There is nothing rude or unsportsmanlike in declining a rematch request. In competitive chess rematches simply don't exist. Just try to play a rated OTB game in a tourney, ask for a rematch and see the reaction.
I'm pretty sure every grand master has played most of their opponents more than once. A lot of tournaments are the best of 3 or 5, and there's always the next tournament. If you don't feel like trying again right now, that's fine, but it's still rude not to at least excuse yourself and ignore your opponent when they're sending you a request. The best you can do is, if not play the rematch then, send a friend request and play it later.
I have nothing against playing same opponent again when the seek algorithm will pair us up in the future.
Please give me an example of a tournament where it's "the best of 3 or 5". I don't know any. In vast majority of OTB tournaments you play an opponent just once. In 10 years of competitive play as a club member I have never played same player more than once in the same competition. And even if more than one game is played it's predefined by the format of the competition. Format here is simple: one game. Rematch button was added as convenient mean to play more games with same opponent when both want it. Then people like use started inventing "rules" around it.
I have nothing to excuse myself for as I do nothing wrong. We agreed to play one game, that's it. If my opponent doesn't write me why he wants to play again I don't see any need to write him why I don't want it.
For what I've heard there are tournaments in which players play multiple games. If not in chess, in most sports. And even if there aren't, as I said, there's always the next tournament. Saying that you would only play with some opponent if you happen to be forced, like if you're lucky enough to be paired by the algorithm once again, is pretty much the same as not being willing to play with that opponent again, as you're not doing anything form your part to allow that rematch to happen. You can argue that you have the right to leave not giving any excuse, since a rematch is an agreement of both parts; and you'd be right; but it's still ignoring a person, it's still rude and it's still unsportmanlike.
I am glad you agree that there are no rematches (in the sense "let's try again") in competitive chess. It might happen that a GM will play same opponent in another tournament. It's no different for me - it might happen I will play same opponent if paired up by seek algorithm. It's not about willing or not to play him again, I just don't care whom I will play next time, I don't have any preference for him vs some other random anonymous player from the internet. What I certainly don't want is to play him again right now. And I don't feel any need to provide an excuse.
I am not totally "ignoring a person", I clicked Decline button. He is not entitled to anything more just because we've played a game. If this is rude, than he is just as rude by clicking Rematch without explaining his motifs. He could say that he liked my style, or that he wants to play 3 games to see who is better, or that his coach told him to always try to rematch. Just to say anything to be polite. But he silently clicked the button, and so did I.
What is unsportmanlike is not decided by you, it's a question of a consensus. If you check all the answers in this and similar threads you will see that vast majority of players think like me.
Again if you don't want to play again right now, send a friend request and have the rematch later. And yes, you're pretty much ignoring your opponent even if you're clicking "decline". There's no difference in what the opponent sees if you don't say anything.
I don't think you're understanding why I'm saying it's rude if you're trying to say offering the rematch is just as rude with no basis. With all respect, that just sounds like a "No, you" argument. The reason I say it's rude is because the opponent is sending you a message and you're offering nothing in return by either declining it or ignoring it, which have the same effect. The least you can do is say something.
I'm not saying it's unsportsmanlike because I claim to define it. I don't know which part of my message lead you to believe I'm claiming to define it. I think it would make a lot more sense to explain why exactly you think this is not if that's your purpose, rather than just saying not just because I say so. But I digress. The reason I say it's unsportsmanlike is because you're basically making sure not to play with that opponent again, unless you happen to be forced by chance. It would be the same if you just wait to see if you happened to be paired up in the next tournament and denying any friendly match.
I don't want to be friends with some anonymous player just because we played a game. He can equally send me a friend request if he wants to, I will probably accept.
If you consider clicking Rematch as a message, then clicking Decline is a message as well. It's totally symmetric. I don't have to say anything because he didn't say anything neither.
I don't see why I have more obligations (like sending a friend request or a text message) just because I won the game.
It's a consensus in online chess that declining a rematch is perfectly fine regarding the sportsmanship and no excuses should be made. You claim that it's unsportsmanlike looks your own invention and your own definition of a sportsmanship. If it's not then please share with us where you took it from.
"Sportsmanship: behaviour in sport that is fair and shows respect to the other players" (Cambridge dictionary). I follow this code of conduct 100%: I don't say anything abusive in chat, don't ask my opponent to resign in hopeless position, don't celebrate my victory in any inappropriate way. You show bad sportsmanship by not respecting my decision not to play another game. You are a rude person blaming others when they do nothing wrong.
I am making sure not to play with that opponent again right now, you see the difference? Not never, just not right now.
Declining the rematch is not sending a message back, as the opponent doesn't receive any kind of notification whatsoever. And even if they did, it's still just like saying "No" and leaving with no further explanation. Yeah, you don't have any obligation to accept it, but again, declining it, specially after wining the first game, and specially without saying anything, is still not very nice, even if it's not against the rules.
The reason I say it's unsportsmanlike is not because you're breaking the rules, being offensive or anything. Rather, I mean it shows a lack of competitive spirit, having a person in front of you that you know is willing to have another game and putting no effort (except maybe for not blocking them) in allowing that rematch to at least happen another day. If what you say about "not never, just not right now" is true, then that's ok: send a friend request or at least a message.
I gave you several examples of what an explanation could be on his side (liking my style etc.) but I don't get any of this. I get no message and no explanation so I don't send any message and give no explanation. It's totally symmetric, equally polite/rude on both ends.
I have competitive spirit - that's why I played a game. The definition of sportsmanship doesn't say that I have to be willing to compete at any given moment. We played the game, now the competition is over. That's the format here when you issue/accept a seek - it's for one game.
My opponent is just clicking the Rematch button, no effort other than that. He could also send me a friend request and a message suggesting that we play again sometimes later but I have never received such a friend request and message after declining a rematch, never. He is making no effort other than clicking a button, maybe after all it's not so important for him, and that's fine because there are thousands of available players willing to play right now.
I don't know why you don't get it. It's simple. Chess game is played when both want it. If just one wants it it's not enough.

I suggest to chess.com they make a choice of TWO Game match. It's automatic then those who are matched must play 2 games. Aborting the 2nd game is loss and loss of rating points.
I propose this Option be available in blitz and bullet.

I completely agree with this. It's so frustrating to not receive a rematch. Everytime I win, I wait to see if my opponent offers one, if I don't offer it myself. And if I have any majority reason that prevent me from playing again, I explain it.
Why to explain anything? My opponent didn’t explain why he asks a rematch, he just clicked the button, I also just click the button - Decline.
We all know the reason anyone asks for a rematch. They want to try again. It's called sport spirit. Declining a rematch request, however, at least after the very first match and having won, is kind of rude and not very sporty. If you see the rematch challenge and you have a reason that prevents you from playing again, the best would be to excuse yourself rather than ignoring your opponent. Then it's understandable. Anyone with a sport spirit will be willing to play with any opponent a second time, if not now, some other day.
I also have a very obvious reason to decline: I don't want to try again right now, no need to explain it in words, a button click will suffice.
There is nothing rude or unsportsmanlike in declining a rematch request. In competitive chess rematches simply don't exist. Just try to play a rated OTB game in a tourney, ask for a rematch and see the reaction.
I'm pretty sure every grand master has played most of their opponents more than once. A lot of tournaments are the best of 3 or 5, and there's always the next tournament. If you don't feel like trying again right now, that's fine, but it's still rude not to at least excuse yourself and ignore your opponent when they're sending you a request. The best you can do is, if not play the rematch then, send a friend request and play it later.
I have nothing against playing same opponent again when the seek algorithm will pair us up in the future.
Please give me an example of a tournament where it's "the best of 3 or 5". I don't know any. In vast majority of OTB tournaments you play an opponent just once. In 10 years of competitive play as a club member I have never played same player more than once in the same competition. And even if more than one game is played it's predefined by the format of the competition. Format here is simple: one game. Rematch button was added as convenient mean to play more games with same opponent when both want it. Then people like use started inventing "rules" around it.
I have nothing to excuse myself for as I do nothing wrong. We agreed to play one game, that's it. If my opponent doesn't write me why he wants to play again I don't see any need to write him why I don't want it.
For what I've heard there are tournaments in which players play multiple games. If not in chess, in most sports. And even if there aren't, as I said, there's always the next tournament. Saying that you would only play with some opponent if you happen to be forced, like if you're lucky enough to be paired by the algorithm once again, is pretty much the same as not being willing to play with that opponent again, as you're not doing anything form your part to allow that rematch to happen. You can argue that you have the right to leave not giving any excuse, since a rematch is an agreement of both parts; and you'd be right; but it's still ignoring a person, it's still rude and it's still unsportmanlike.
I am glad you agree that there are no rematches (in the sense "let's try again") in competitive chess. It might happen that a GM will play same opponent in another tournament. It's no different for me - it might happen I will play same opponent if paired up by seek algorithm. It's not about willing or not to play him again, I just don't care whom I will play next time, I don't have any preference for him vs some other random anonymous player from the internet. What I certainly don't want is to play him again right now. And I don't feel any need to provide an excuse.
I am not totally "ignoring a person", I clicked Decline button. He is not entitled to anything more just because we've played a game. If this is rude, than he is just as rude by clicking Rematch without explaining his motifs. He could say that he liked my style, or that he wants to play 3 games to see who is better, or that his coach told him to always try to rematch. Just to say anything to be polite. But he silently clicked the button, and so did I.
What is unsportmanlike is not decided by you, it's a question of a consensus. If you check all the answers in this and similar threads you will see that vast majority of players think like me.
Again if you don't want to play again right now, send a friend request and have the rematch later. And yes, you're pretty much ignoring your opponent even if you're clicking "decline". There's no difference in what the opponent sees if you don't say anything.
I don't think you're understanding why I'm saying it's rude if you're trying to say offering the rematch is just as rude with no basis. With all respect, that just sounds like a "No, you" argument. The reason I say it's rude is because the opponent is sending you a message and you're offering nothing in return by either declining it or ignoring it, which have the same effect. The least you can do is say something.
I'm not saying it's unsportsmanlike because I claim to define it. I don't know which part of my message lead you to believe I'm claiming to define it. I think it would make a lot more sense to explain why exactly you think this is not if that's your purpose, rather than just saying not just because I say so. But I digress. The reason I say it's unsportsmanlike is because you're basically making sure not to play with that opponent again, unless you happen to be forced by chance. It would be the same if you just wait to see if you happened to be paired up in the next tournament and denying any friendly match.
I don't want to be friends with some anonymous player just because we played a game. He can equally send me a friend request if he wants to, I will probably accept.
If you consider clicking Rematch as a message, then clicking Decline is a message as well. It's totally symmetric. I don't have to say anything because he didn't say anything neither.
I don't see why I have more obligations (like sending a friend request or a text message) just because I won the game.
It's a consensus in online chess that declining a rematch is perfectly fine regarding the sportsmanship and no excuses should be made. You claim that it's unsportsmanlike looks your own invention and your own definition of a sportsmanship. If it's not then please share with us where you took it from.
"Sportsmanship: behaviour in sport that is fair and shows respect to the other players" (Cambridge dictionary). I follow this code of conduct 100%: I don't say anything abusive in chat, don't ask my opponent to resign in hopeless position, don't celebrate my victory in any inappropriate way. You show bad sportsmanship by not respecting my decision not to play another game. You are a rude person blaming others when they do nothing wrong.
I am making sure not to play with that opponent again right now, you see the difference? Not never, just not right now.
Declining the rematch is not sending a message back, as the opponent doesn't receive any kind of notification whatsoever. And even if they did, it's still just like saying "No" and leaving with no further explanation. Yeah, you don't have any obligation to accept it, but again, declining it, specially after wining the first game, and specially without saying anything, is still not very nice, even if it's not against the rules.
The reason I say it's unsportsmanlike is not because you're breaking the rules, being offensive or anything. Rather, I mean it shows a lack of competitive spirit, having a person in front of you that you know is willing to have another game and putting no effort (except maybe for not blocking them) in allowing that rematch to at least happen another day. If what you say about "not never, just not right now" is true, then that's ok: send a friend request or at least a message.
I gave you several examples of what an explanation could be on his side (liking my style etc.) but I don't get any of this. I get no message and no explanation so I don't send any message and give no explanation. It's totally symmetric, equally polite/rude on both ends.
I have competitive spirit - that's why I played a game. The definition of sportsmanship doesn't say that I have to be willing to compete at any given moment. We played the game, now the competition is over. That's the format here when you issue/accept a seek - it's for one game.
My opponent is just clicking the Rematch button, no effort other than that. He could also send me a friend request and a message suggesting that we play again sometimes later but I have never received such a friend request and message after declining a rematch, never. He is making no effort other than clicking a button, maybe after all it's not so important for him, and that's fine because there are thousands of available players willing to play right now.
I don't know why you don't get it. It's simple. Chess game is played when both want it. If just one wants it it's not enough.
"The competition is over." That's exactly what I mean that shows a lack of competitive spirit. No one with a competitive spirit would want their first match with someone to be their last match. Or any match.
Again, saying "if declining without saying it is rude, then sending it without saying it is rude too", without any basis is just the equivalent of a "No, you" argument. I'm explaining why the fire one is rude: Someone's saying "Would you like to play again", and you're ignoring them.
Also, I think you took to literally the word "effort" and now you're trying to argue the opponent doesn't put effort either, because pressing a button is easy. That's not what I mean. I'm saying you're putting nothing from your part to allow that rematch to happen, and leaving it, if anything, to the chance. Similar to denying someone any friendly match and saying "If we happened to be paired in some other tournament, then we talk."
THAT WOUILD BE A VERY VERY STUPID RULE.