Checkmate Challenge

My online chess camps this summer have been competing with one another in the checkmate challenge. The challenge consists of 30 minutes of solving as rapidly as possible checkmates in one move. I use a database of 101 exercises that I downloaded from the web so long ago that I no longer know where or when. I believe it may have been Gunther Ossimitz's now defunct chess site (see "Gunther Ossimitz PGN Files").

The first ten exercises are mate with a rook. Then there are ten with a bishop. These are followed in succession by mates with a knight, a queen, and then pawns. Three involving en passant captures usually slow the students down, and I often need to explain the rule.

White to move

Mate in one

Some pawn mates are the pawn delivering the final check. Often, the pawn promotes to a rook or queen. In one case, the pawn must become a knight.

After the en passant mates, there are some double checks mixed with other themes. The exercises grow slightly more difficult. I like the structure of the database, which resembles the structure at the heart of the work of Viktor Khenkin. See "Two Old Books (and one new)" for more about Khenkin.

Many of the exercises are composed, and the early ones have few pieces. Some are from familiar games, such as Morphy's Opera Game. 

My students have included a handful of strong youth players, but most are beginners. Some of them have been playing chess a week before camp begins. I ask the students to shout out answers or type them in the Zoom chat. Speed matters. Wrong answers are ignored if the right answer comes fast enough.

Many groups have solved 60-70 of the exercises in the 30 minutes. Three groups have solved all 101! Today, a group solved the whole set in 27 minutes. Last week, a group did so in 26 minutes. One group with some skilled players whipped through the entire set in 18 minutes.

These are some of those that slow the students in their quest. It is always White to move.