Seeing Patterns

Tal's Winning Chess Combinations (1979) has influenced my perception. Last week, I read the first chapter of this book by Mikhail Tal and Victor Khenkin, which exists under several titles with and without Tal's authorship. This chapter concerns the rook and corridor checkmates and checkmate threats. These corridor vulnerabilities are most often back-rank weaknesses, but there are other corridors, including a position where a rook must be given up to avoid checkmate between two walls of pawns alongside the f-file.

The large number of deflection combinations to threaten checkmate has made me more alert to these possibilities when going through other games. Of course, these ideas are not new to me. I was familiar with the idea even before Lev Alburt's Chess Training Pocket Book (1997), which I read fifteen years ago, stimulated my imagination for the maneuvers with this exercise.

White to move

Alburt gives the exercise the title, "Defection Detection". It is number 93 in the book.

This morning, I was reading Baskaran Adhiban's annotations to his draw against Wesley So at the Tata Steel Chess Tournament in January when the deflection motif jumped into my perception. After 25.Bxa7, So could have played 25...Rxa7. He did not, playing 25...Bxc3 instead.

What if he had grabbed the bishop?

White to move

Immediately, I saw 26.Qd5+ Kh8 27.Qxe5. However, nothing compels the suicidal 27...Rxe5. So would have had choices: 27...Raa8, 27...Qb6+, and others. In Adhiban's case, his offer of a bishop wins So's bishop, but no more. The game, as he points out, was, "[a]n exciting draw with lots of interesting twists!" (Chess Informant 131, 49).

Missed Chance

Baskaran Adhiban won the challengers group in the 2016 Tata Steel Chess Tournament, earning a position in the top section this year. He stood one place above last after four rounds, having lost two games and drawn two. The commentators were beginning to discuss how the winner of the challengers group often gets clobbered when they move up to the top group.

In round five, Adhiban put an end to this conversation. He beat Sergey Karjakin! He did not lose another game through the rest of the tournament and finished tied for third place with Wei Yi and Levon Aronian.

He might have finished even stronger. In round eleven, he reached this position against Magnus Carlsen, who finished the tournament in second place.

Black to move

The game ended in a draw. Can you find the combination that Adhiban missed?

Hat tip to Daniel King's PowerPlayChess video on this game.