Originally posted by piderman
Server load would be increased tremendously. You see, with checkmate, you only check the 0 legal moves when someone is checked, and then only the ones for the king (move, take, putting somthing inbetween). With the one legal move, you would have to check on EVERY possible move EVERY move for EVERY game. That would take a lot of computation time. Therefore not a feasible option.
Not so fast! I referred to stalemate, not checkmate.
If the king is not in check, but the player whose turn it is has no legal move, the game is a draw. Therefore, the server already has to check (every turn) that there is at least one legal move; this may involve considering every piece. A check for a forced move stops when two moves have been found, it does not check every possible move.
You might protest that checking for two moves is twice as much work as checking for one, but as an addition to the other things that must be done every turn, it would not come to much.
Nonetheless, even though it might speed some games up, this remains a bad idea, definitely patronising to the defending player and possibly giving him unfair assistance.