1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6
5. Nc3 a6 6. f3 e6 7. Be3 Nbd7 8. Qd2 Be7
I've been studying games instead of playing for the last month or so. I observed a game yesterday where White played a King move (Ke2) in the opening which was so bad that he must of intended to play 0-0-0 instead. So, a mouse slip, you would think.
White quickly asked for a take back but Black refused.
I believe the time control was 10 minutes.
In my opinion Black, in a spirit of good sportsmanship, should have allowed the take back.
The move is not a blunder in the since that it loses instantly.
Any opinions on this would be welcome.
My personal view is not to allow takebacks (or to request them) at all - the situation is just too easily abused. Most are not so black and white as your example, and putting the opponent on the spot, asking that they use their time to consider the request (and disturbing their train of thought in so doing) is not something I like.
Better to accept that slips (which I have done myself too, of course) are just something that we must guard against doing - just another error to avoid.
When the player very obviously made a mouse slip in a longer time control. If I have any doubt that it wasn't a mouse slip then I won't adhere.
Learning through pain. That should every chessplayer do.
I dont give takebacks, some few exceptions in the longer time controls. Usually when my opponent fails to castle and it's really obvious. I also consider the time it takes my opponent to request the takeback when deciding. But maybe I'm disturbing my train of thought too much with this as @ChesterDog said.
Almost never. Unless it's a very obvious mouseslip. But in fast time controls, hey, the point it to think fast, if you make a mistake, tough. And in longer time controls, well, you have the time to think. Use it wisely.
I give takebacks most of the time.
Usually in this cases:
1. An obvious mouse-slip.
2. The opponent somehow missed an obvious en-prise piece.
The only case I remember I didn't give a takeback was when the opponent had a difficult threat to defend and couldn't find the proper defense after a long thought, only after he moved.
I also tend to decline takebacks when the opponent obviously missed a tactic (not an en-prise piece) which he saw only after he moved.
Typically, I accept takeback requests. I myself only request a takeback for mouse-slips, as whilst I believe Chess shouldn't have an undo button, I also feel that if your intention was to move elsewhere, then that should be where your piece is moved. I accept takebacks in most situations, even when they clearly aren't mouse-slips.
I tend to accept takebacks without question as to why if it was made shortly after the opposition made a move. If after a period of time, they request, I attempt to engage in conversation, requesting why they asked for a takeback. If they are honest and state a mistake they believe they made after such time, I takeback no problem. If they try and lie, claiming it was a mouse-slip after idk, 30s wait, I have my doubts and don't accept.
If I make my move, perhaps exploiting a blunder they made or whatever, and they then ask for a takeback, depending on the player, I accept. If I know the player, or they seem to have good sportsmanship (previously accepting a clear mouse-slip or whatnot), depending on the move, I accept takebacks. If they blundered something like a Bishop, a Knight or perhaps a Rook, I typically wont accept after I made my move. But if it's something simple and they lose their Queen due to it, I accept sometimes. If I am playing a random person, I tend to also only accept 3 takebacks, no more.
tl;dr I am awfully generous with takebacks.
Edit: I don't accept takeback in 3+0 or faster time control.
take backs are not part of chess. Dont ask for them nor do I ever grant them (blocked from settings).
I block them in settings.
I'll accept take-backs in real life, in casual games only. In anything time-controlled, never. People need to learn to resign and play again, rinse and repeat. On this website, so many people refuse to resign and also refuse to rematch.