I think this is because chess.com doesn't grant the draw automatically. You have to claim it by clicking the "offer draw" button.
Perpetual Check

But then your opponent can refuse, and whomever starts the perpetual checking with a time advantage wins the game. Seems like that should be built into the engine.

I think this is because chess.com doesn't grant the draw automatically. You have to claim it by clicking the "offer draw" button.
FIDE rule http://www.fide.com/component/handbook/?id=124&view=article
9.2 The game is drawn upon a correct claim by the player having the move, when the same position, for at least the third time (not necessarily by a repetition of moves):
a. is about to appear, if he first writes his move on his scoresheet and declares to the arbiter his intention to make this move, or
b. has just appeared, and the player claiming the draw has the move.
Positions as in (a) and (b) areconsidered the same, if the same player has the move, pieces of the same kind and colour occupy the same squares, and the possible moves of all the pieces of both players are the same.
Positions are not the same if a pawn that could have been captured en passant can no longer be captured in this manner. When a king or a rook is forced to move, it will lose its castling rights, if any, only after it is moved.
If nobody claims the draw you continue playing "That, if we count correctly, is a thirteen-fold reptition. What happened? Apparently van Wely was annoyed with his young opponent, ...".

But then your opponent can refuse, and whomever starts the perpetual checking with a time advantage wins the game. Seems like that should be built into the engine.
It is an offer he cannot refuse. http://support.chess.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=141
The difference from OTB is the player makes a move then claims the draw.

To note: if threefold repetition does not arise, you must play 50 moves without a capture or pawn move, then you can also claim the draw.

Thanks folks for your prompt replies. Sometimes, just 3 repetitions, game draws automatically - my be in this case, my opponent must have been claiming for a draw. It makes sense, I should have actually claimed.
What about in correspondence chess? The FAQ says:
In correspondance chess, once your opponent has made 3 moves the same (or 50 move rule), make your move, then submit the move, go back into the same game. Just below the notations box there will be text for you to click on that says "claim game".
Click on that to claim the draw by repetition.
But I don't see any such text to click, and I don't know what they mean by the "notations box". Anyone know more about this? TIA


Well to make it clear to you. If its 3 fold rep/50 no capture + pawn move etc..., then just click the draw button and its AUTOMATICALLY DRAWN, dont need both players to confirm etc, just the first person to click draw (if it turns into "claim draw", so be it) will turn the game into a draw. Im assuming you just didnt click draw then did you...? If you did then thats strange, but he should have accepted your draw anyhow. If its your friend, you should have offered him a draw anyway lol. If its some1 else who your winning against, and you dont want to draw, well kay you mite not want to draw, but in this case its your friend and you well... You should have clicked the draw button is all im saying ^_^.

But then your opponent can refuse, and whomever starts the perpetual checking with a time advantage wins the game. Seems like that should be built into the engine.
Actually there is no "perpetual check" in the laws of chess. As pointed out by others, perpetual check would eventually fall into one of 2 categories, 3-fold repetition or 50 move rule.
And in these cases draw is not automatic but have to be claimed.
So there is nothing to be built into chess.com engine

On other chess sites this is handled optimally by the "offer draw" icon changing to "claim draw" when pertinent.
Hoping chess.com will eventually do the same.

I disagree -- the text on the button should not change at all. It should be entirely up to the player wishing to claim the draw to know that the conditions under which he can do so has been met. Why should the site give a player that information?

I disagree -- the text on the button should not change at all. It should be entirely up to the player wishing to claim the draw to know that the conditions under which he can do so has been met. Why should the site give a player that information?
You are not really giving the player an "information" since it's not something secret that you can claim if you notice or leave it if you don't. No. It's a chess RULE saying that "if the same position arises on the the board three times it's automatically a draw" more or less.
I'll tell you more - I don't even think that any of the players should click the button to claim the draw, but the system itself should call the draw after the threefold repetition.
Regards.

If you will scroll a mere twelve posts up, you will see that the rule is a threefold repetition must be claimed as a draw. If nobody claims it the game continues.

I disagree -- the text on the button should not change at all. It should be entirely up to the player wishing to claim the draw to know that the conditions under which he can do so has been met. Why should the site give a player that information?
You are not really giving the player an "information" since it's not something secret that you can claim if you notice or leave it if you don't. No. It's a chess RULE saying that "if the same position arises on the the board three times it's automatically a draw" more or less.
I'll tell you more - I don't even think that any of the players should click the button to claim the draw, but the system itself should call the draw after the threefold repetition.
Regards.
The rule may not be a secret, but informing the players that the situation has arisen in their game is specifically providing information about the current position.

I disagree -- the text on the button should not change at all. It should be entirely up to the player wishing to claim the draw to know that the conditions under which he can do so has been met. Why should the site give a player that information?
You are not really giving the player an "information" since it's not something secret that you can claim if you notice or leave it if you don't. No. It's a chess RULE saying that "if the same position arises on the the board three times it's automatically a draw" more or less.
I'll tell you more - I don't even think that any of the players should click the button to claim the draw, but the system itself should call the draw after the threefold repetition.
Regards.
The rule may not be a secret, but informing the players that the situation has arisen in their game is specifically providing information about the current position.
Yes, but what's the problem with that? The rule says it's automatically a draw, not that you CAN optionally call a draw if you want to. It's a draw and the system should call it.
If you play online here or in any other server, after the threefold repetition, the game stops. You can check it.
It's very absurd, but it's like saying that if you don't notice that you have checkmated your opponent and don't claim it, you can keep on playing.
Regards.

Yes, but what's the problem with that? The rule says it's automatically a draw, not that you CAN optionally call a draw if you want to. It's a draw and the system should call it.
Wrong. The rule requires either player to CLAIM the draw after the repetition has occurred. This is true in both OTB chess and here on chess.com!

It's very absurd, but it's like saying that if you don't notice that you have checkmated your opponent and don't claim it, you can keep on playing.
As Nytik has already pointed out, these two rules are not structured the same way. The rules are clear that a game is over once one of the two sides has been checkmated by the other, however it leaves the declaration of a draw in the event of three-fold repetition or 50 moves without a capture or pawn move entirely up to the players. Unlike checkmate (or stalemate for that matter) there is an option to play on.
Both rules are also implemented properly here.
What is the rule on perpetual checks? Today 19th Aug 2010, I gave to my opponent [ Hashimi] (1536) 30 perpectual checks. But the game was not drawn despite both of us moving to the same squares. Finally my opponent friend won on time. Its OK no problem but I don't know if this is a bug (?) in the chess.com