Just a quick question. I’m playing chess by e-mail with a friend and I can see I’ve got a definite mate in six. Since I don’t know if he’s seen it, should I keep playing or let him know he’s beaten? I don’t want to appear condescending, but at the same time I don’t want him to know he’s wasting his time. What do you reckon?
It’s been decades since my last chess-by-mail play but in those days I would send an “all variations” analysis when I had a mate-in-x. Depending on the opponent and whether the game was “serious” or not (as in part of some official tournament or the like) such a gesture was normally treated with courtesy and acknowledgment of my thoroughness. There were some opponents who insisted on playing it out, but not many. There were even some who didn’t respond to the analysis at all.
All that said, I doubt if I had more than five games where the issue even came up in “serious” play.
I think it depends on how strong each player is as well. I rate myself as a reasonable chess player (about third-team standard at your average club, I would think), and six moves seems a lot of variations to work out, unless all the opposition replies are forced. If they are, I think sending the analysis is reasonable (or if there are really only 2 or 3 lines to consider), but I wouldn’t do it unless I was 100% certain that I had not overlooked anything. Perhaps that goes without saying, in which case forgive me - no condecension on my part is intended!
For all practical purposes, saying “I have mate in six” and “Checkmate” are the same thing.