If Only...

Chess engines deflate our egos. I thought I had played a reasonably strong attack, but chessdotcom's "coach" wryly remarked about my star move, "Curious move. Maybe not exactly what the position demands--but an interesting idea." The engine has my move at +6.4: clearly winning! What did the position require?

White to move

Theoretical Position

In this diagram position, White has a forced checkmate in seven moves. I had rejected the move that might have led to this position because I wrongly believed that Black's king was relatively safe from further abuse on f7.

After 20...d5, the game reached this position.

White to move

The time control was ten minutes and I spent nearly three minutes considering 21.Nd6+ and 21.Nf5+, which I ultimately played. I quickly rejected 21.Qh6, as noted above. Both 21.Qh6+ and 21.Nd6+ are superior to 21.Nf5+.

After 21.Qh6+, the computer's best line continues 21...Kg8 22.Nf6+ Kh7 23.Kf2. Instructive, but humans do not see these things. After 21.Qh6+ Kf7, the position in the diagram at the top of the post would have been reached.

After 21.Ne6+, 21...Bxe6 loses quickly and I should have been able to calculate that line. Maybe I did. I recall only that I saw something that seemed unclear. For instance, the bishop is not required to capture the knight.

The game continued:

21.Nf5+ gxf5

I was prepared for 21...Bxf5 22.Rb7+ Kf8 23.Qh6+ and probably considered a move or two deeper. I was certain that good moves would be available.

22.Qh6+ Kf7 23.Qxf6+ Kg8

Here I began to struggle to find the best moves, but reliably kept up pressure until my opponent resigned seven moves later.