Why do people assume you are cheating?

I agree with you people but i saw game where rang 1200 was playing against rang 1800 and won in 12 moves.it is not posible to rating 1800 dont see fork ,and also it is not posible that rang 1200 make mating attack and sacrifise queen and knight for mate in 10 moves.Also when you lose with opponent that is same rang as you you will lose minimum points so people use cheating programs to win against stronger oponents.smart people will not use program all the time and will not play always best moves.Also dont forget 90% of those players are kids who want to be best in everything,or people who are not good at board.after all this is just for fun.the real challenge is on board,in person,when you play against clock also!!!

I cannot see why anybody would think you're cheating with the rating you have?  

I have been accused of using a bot several times, but this is generally when I had a just got an account and have been racing through from 1200 to over 2000 in a couple of hours playing 3-0 blitz tournaments.

It's understandable when I beat 1800-2000 rated players when I'm rated hundreds of points below them...but it's just sour grapes.

I might not bother playing slow play games though, as it's very easy for people to cheat on these, so pretty pointless.  I might as well study with a computer on my own.

It's easier for some people to accuse their opponent of cheating than realise they just played badly themselves.  I look at the notes page of every player I play after I kick off a game and it's amazing how many have notes from people claiming them as cheaters (second only to the childish "runner, no rematch" nonsense).

Occasionally I'm slightly suspicious about some opponents, but I don't dwell on it and certainly don't post it on their notes page.  I make plenty of mistakes and sub-optimal moves so someone certainly doesn't need a computer to beat me!

Jess, why bother and so what. Truth is, it's their loss! How boring and just plain stupid. I never even thought about it and didn't know people did that. Also, if someone accuses me its all their anxiety because I know I don't. I guess I'd just thank them for the compliment!

But beauty of chess is to be at board..That you calcute your moves,your opponents moves,to see his face and that you know is he pro or not.maybe i am not good so thats why i dont like anything below 15I10 but to force my mind to think deep into only one game for 3 or 4 hours that is chess.everything below 15I10 my brain can not start thinking.if i need speed i will drive motor or car :)

The few times i have been accused of cheating, I thank them.  If i am cheating, i am using the worst chess engine ever made.  

CensoredReality, right on.  Not to say it doesn't happen, but I can't understand the enjoyment anyone would get out of using an engine to play  against an opponent.  Certainly this is rare. 

The one case where I suspected someone of cheating was actually when they botched the opening the first game, and in the next game with the same colors, I played the same opening and this time the opponent played it like a book, even finding a book move that was theoretically best but counterintuitive as it appeared to hang a pawn.  As a way to cheat, that sounds a lot more appealing to me: survive the opening by using a database, get a decent position, then turn the engine off, and maybe you'll even remember how to deal with that opening in the future.  Surely this form of cheating is more common.

No, I don't use chess software.  I actually hate using fritz to even analyze my games after the fact, simply because I don't like some of the lines the computer comes up with.  Maybe I have a bad engine...

Off topic, but there's something you have to understand with engines. Engines are superior to humans. They have no emotion, no bias of,"oh, that looks scary" or,"oh that looks good" it only cares if it is actually scary, or if it is actually good. Also, it can see far deeper than a human could hope to. So your engine only tells you that a given move is the best is because there is a follow-up move, and if that follow-up move is not played, that previous move is actually not so good. Say, in this position:

you play Rb8, which is one of the best moves. It forces Kh8, from which you take the Bishop with checkmate. But, if you actually played Rb8 to play Rb4, hang your Rook, and give black a passed pawn that cannot be stopped, Rb8 was actually a bad move because that was your follow-up, not Rxf8#. In other words, the lines your engine shows are objectively good, but only if you see the idea and play the idea. Engines are weird in this way, and in order to do your best in analysis, you need to analyze all the lines of when the engine says a given move is best.

In B4 the Lock!!

Tantrums.

Because they took up chess, thinking they were going to be good at it and they are just bad, or in some cases awful. So they blame their lack of skill, hard work or preparation on others who trounce them easily.