GNOME Bugzilla – Bug 691053
Issues with insufficient material detection
Last modified: 2013-04-15 04:26:09 UTC
* King and two Knights vs. King is not insufficient material, but we say it is. (It's impossible to force an optimal opponent into checkmate from this position, but an inattentive player can lose.) The draw should only occur once another Knight has been lost. * King and minor piece vs. King and Knight is not insufficient material, but we say it is. This is definitely not a big deal - it's really hard to lose from this position - but it'd be technically correct to force this to play out.
Created attachment 232611 [details] [review] Fix I'll do a patch for only the first situation if requested.
I forgot to add, the testcases I added for this situation will fail until https://bugzilla.gnome.org/show_bug.cgi?id=691050 is applied.
Comment on attachment 232611 [details] [review] Fix LGTM
The following fix has been pushed: 3a0a4d6 Insufficient material fixes
Created attachment 241542 [details] [review] Insufficient material fixes Although two knights cannot FORCE a checkmate, the opponent can blunder. This position is not a draw. Also, if each side has one minor piece (unless they are two Bishops on the same color) the game is - surprisingly - not drawn. With the extra piece you could wind up in a checkmate that's not possible if the King is on his own.