A Pattern

The relationship between two puzzles on chess.com surprised me Wednesday morning and I made it that afternoon's lesson for my beginning students. Sometimes I use this feature of the website and iOS app regularly. During the first fifteen years that I was a member of chess.com, I only did puzzles occasionally, completing fewer than 5000. That changed in December 2022 and I've completed nearly 17,000 in the past three years.

Wednesday, I completed 41, failing 13. One that came up early in the session took me five seconds. This mating sequence crops up most days, as it did again this morning. It also appeared in the last puzzle Wednesday morning, but with a twist that took me nearly a minute to recognize that it was essentially the same.

Because the website only shows me the past 30, I was not able to put the early position in front of my students. Instead, I found a game played by Adolf Anderssen in 1861 that finished with the same idea.

White to move

The first student to offer a solution suggested 21.Bxg7, but after 21...Nxf2+ 22.Rxf2 Kxg7, it was clear that White was worse. We did not look at 22.Kg1 Nh3+ 23.Kh1, but Black has two good choices that neutralize the attack.

The students then saw the correct 21.Rxg7+, but I had to show them the key idea after 21...Kh8 22.Rg8+! and mate follows when the other rook comes to the g-file.

This morning's version took me six seconds.

Black to move

20...Rxg2+ 21.Kh1 Rg1+ 22.Kxg1 Rg8+ 23.Bg5

Sometimes, in the puzzles that chess.com feeds me, there are several pieces that can step into the line of fire and increate the move count.

23...Rxg5#

Seeing the same pattern in this next exercise took longer and brought a pleasant surprise. My young students did not see it until I showed it to them.

Black to move

30...Rxg2+ was obvious, but I did not play it until I saw the follow up after 50 seconds. 31.Kh1 Rg1+ 32.Kxg1 (32.Kh2 also leads to mate on the move) 32...Qxg3#.

Chess patterns are familiar ideas in slightly different positions. Good puzzle books and sometimes chess websites help aspiring players learn and train recognition of these ideas. The first two volumes of The Manual of Chess Combinations by Sergey Ivashchenko are particularly good in this respect.