Do chess players play their best after winning or losing?

This is how it works for the majority of chess players.

When losing a game in a tournament a player usually plays the next game not the best he can.

He is frustrated from the loss in previous game and can't the lost game out of his head.

But if a player is winning a couple of games in a row he gets a mental boost from his victories and will do everything he can to win another game.

True or false?

very true...all my otb tourneys have gone quite well after winning the 1st game...losing the 1st game usually meant playing well below my strength...its a psychological thing i suppose☺

but yes...i guess some players dont really think about losses too much until after the tournament so they can still do well

Still the majority of the players don't play their best after hard losses. 

Actually I think the performance gets affected from understanding the reasons you went wrong in the first game. If you convince your self it was a bad moment of inaccurate thinking and not some specific problem in the way you approached the game, your technique, or your strategic choices then I believe you have more chances to come back in a good performance with a acceptable result. Draw or Win.

The fatal is when you lose confidence in to your own general playing ability. I think determination is the key.

In every sport , all players with low level of determination have problems to come back them selfs from a bad result.

Depends how strong you are mentally. I guess its the same when you blunder. How you react to that blunder is as or more important than the blunder itself. Everyone blunders, everyone loses a game, so if that is a constant, then the variable is one's reaction to it. But psychology plays such a large part in chess, I'd agree that a loss would at best still change the way you play your next game. For me personally, it depends on the day. Sometimes a loss makes me more determined to win, so I concentrate better, sometimes I get frustrated. I have never seen or heard anyone say frustration is a key to victory. But i guess it is easier steaming over a loss then stiff upper lip and all😉

I can't play mad. I'll end up making suicidal sacs that rarely work and things like that. If I have a tough loss I just shake it off and call it a day.  Guess I would have to play on in a tournament setting. On the other side of the coin If I beat someone that I know is stronger than me and know I played a great game, I'm on top of the world. I'll take anybody on lol. 

Lots of players lose after they lose a game.  This is reasoned by blaming being out of form, sick, or some other excuse.

I play more aggressively after losing, but this maybe more of playing a lower rated player due to the Swiss system.

I don't really notice, at least not based on wins and losses. If I'm playing poorly or well (relative to what I think my norm is) I may be frustrated or confident. This is separate from the result. I can play badly and win, or play well and lose.

I tend to double down after a loss to try to prevent another. I'll go outside the hall and play a few blitz games on my phone or something to get my mind away from the previous game and focus on the next.

That's probably true....but maybe it is because you ate too much before the match, just don't really feel like playing that particular day, lack of preparation, or some other intangible reason?

Generally play my best while I'm losing.

Previous performance is irrelevant to the outcome of a current game, in my experience. Although losing/winning streaks do happen, occasionally.

I don't think it's a hard-and-fast rule, but I think that it is True in general.  Most of the tournaments where I've been a USCF TD were scholastic events so my observation is based on teenagers who tend to reach higher highs and lower lows over wins and losses than adults.

Additionally, it may not be an emotional thing brought about by winning and losing.  Sometimes we're distracted by something going on in our lives not related to chess, sometimes we are tired or not feeling well, etc.  Those things can drag down our performance.

Then sometimes we just don't think clearly.  When i solve tactics problems, I may get 12 out of 13 correct one day, then only six out of ten the next and spend an hour each day - the problems are roughly equal difficulty and I often can't explain why there's such a difference.

after a loss i try to do my best as it turns out to be DO OR DIE.

I've found that it works that way within a single game, for most players:

If a player makes a blunder, he tends to lose his objectivity and start making additional unforced errors. Bad positions tend to generate bad moves, almost automatically.

I agree that it works like that within single game too. But in consecutive games as well. I would say that in bad positions it is difficult to find the best moves, so mistake follows mistake pretty often.

I second this. And you really can't say the majority of players do this or that. You're just going off the way you play and you see everything from that perspective. Many players would play better after a loss because they become more determined and it also removes the stress of not wanting to lose.

For reference: 

*In a U1500 section, I lost my first two games - then I won my last 3. 

You need to be mentally resilient if you want to play chess OTB.