...or blitz, or rapid, or any time format actually. Works best when there is no increment.
Suppose you have a totally winning position (possibly with multiple queens?!), but you are extremely low on time. If you just try to checkmate your opponent, you might run out of time and even end up losing the game! Instead, if you're not confident that you can deliver a checkmate in time, then consider simply eliminating all of your opponent's pawns on the board (and pieces, for that matter, but especially pawns). Why?
A pawn can promote to a queen, which means that technically, the opponent has a chance of checkmating you. But when you eliminate all of their pawns, they cannot possibly checkmate you - bishop alone, or a knight alone, is not enough to deliver a checkmate. This means that IF you lose on time, the computer will register it as a tie due to Insufficient Material vs Time out. Better than a loss!
I know, I know, in the previous tip I literally just mentioned that you should collect the opponent's pawns. But if you think you have enough time, and you are looking for a checkmate, perhaps it's wise to not take EVERYTHING. Here's why.
Leaving at least a pawn for the opponent ensures that a stalemate is not possible. Of course, the pawn must be able to move, otherwise it's useless!
Sometimes, you're just dead lost but you have one thing going for you - your opponent is extremely low on time.
Check out this game by IM Erin Rosen and World Champion Magnus Carlsen:
In this game, black was absolutely lost. So he made a sneaky move Qf1+, hoping to take white's queen on f6. In any other time format, this is definitely a blunder - black just hang his queen - but in this case, this is justified seeing as they only have less than 3 seconds each. Unfortunately for black, white anticipated it and prevented it, but in many cases this can be extremely effective.
This is similar to the previous example, but in this case the purpose is not to snatch a piece - instead, you're looking to flag your opponent. When the opponent has less than a second or so left on his clock, you can make a suicidal check to force your opponent to move his king. Usually, they will have had a premove, so by making a desperate check, you disable the premove and gain valuable time. Your opponent will surely lose due to reaction time.
Note: "flagging" in chess means to win on time. It's considered "dirty" in the sense that you can win a totally lost position just by premoving your pieces every time.
In this video, IM Levy Lozman (white) was playing against an anonymous GM (black). Here, white was totally winning, and black was extremely low on time. To secure the win, white played a blunder-not-blunder check to force the opponent to lose on time.
... I feel guilty writing this. But they're simple, effective tips to take your online rating to the next level, just... be warned, it is extremely frustrating when you are the victim of such nasty tricks.
