Black to Move #6 - Real Chess Game

[ChessChef]

Black to Play, Mate in 6 Moves, from a Real Chess Game


This is from a blitz game that I played on the internet. I was lucky enough to be Black here, and played the key move, which was somewhat intuitive. Then my opponent thought for about ten seconds and resigned. Later on, I analyzed the game with a chess computer and it saw something I did not see, a mate in six. Of course, I felt it was winning at least...I was a piece up at the time and just wanted to trade down. (I doubt my opponent saw the mate, too.)

I saw the evaluation number indicating mate, but I did not look at the line the computer gave, so I stared and stared until I found it. It had much deeper content than I thought it would.

Turns out, the best defense for White was a little shocking to me and the follow-up for Black to achieve the mate in the allotted number of moves was not so easy to spot.

The finale, at least in the line I have analyzed, is very pretty. I haven't checked it for flaws or by-play. Still, not bad from out of the blue.

[ChessChef]

Okay. With some chess problem software I found on the internet, I analyzed the problem again. And came to some conclusions.

Yes, for problem buffs it has flaws.

The first flaw is that Black has two available responses after 1.Be4 Qh2 (the only defensive first move that will
prolong this thing to six moves) 2.Nxh2 Kxh2 3.Qg5 (this is the move that did not jump right out at me since I leaned on playing the check, Qf4+) g4, when he can checkmate White in three moves beginning with either 4.Qf4+ (the one I found) or 4.Qd2+ (the computer is right...it also makes sense to jump onto White's second rank).

The second flaw is that Black also has two responses after 1.Be4 Qh2 2.Nxh2 Kxh2 3.Qg5 g4 4.Qf4+ Kg1, when it's a mate in two beginning with either 5.Qf3 or 5.Qg3+ (the one I saw first, of course, because it's a check).

So, the prettiest mate in all this mess is:
1.Be4 Qh2 2.Nxh2 Kxh2 3.Qg5 g4 4.Qf4+ Kg1 5.Qg3+ Kf1 6.Bd3#, with a Q/B crisscross.

The direct point of the key Be4 is that Qxh3 is threatened, since the g pawn is pinned! That was actually all
that I'd considered in the heat of battle. It was a blitz game.

Wouldn't win any prizes, but this sixer, I must admit, is very efficient.