December 28th, 2025
Christmas Puzzle 8 – Retro
This one is T. R. Dawson’s most famous retractor:
Thomas R. Dawson, Chess Amateur 1920

White retracts his last move and delivers a mate in two
Question: what move could White possibly retract to get a position in which he can mate in two moves. Naturally, he must adhere to all laws of chess, and all problem chess conventions.
Solution: take back h2-h4 and play 1.h2-h4! g4×h3 e.p. 2.B×g6#. The convention in chess problems is that an en passant capture is only allowed if the two-step pawn move has just been played. John Tromp wrote "First time I see a retractor reach the same position!"
Christmas Puzzle 9 – Retro
Retractors by Zvi Roth in Al. Hamishmar 1970

In each case, White retracts one move and then mates in one
Solution 1: Take back 0-0 and play 1.Rh3#
Solution 2: Take back d5×e6 e.p. and play 1.Rd8#
A wonderful realization of two special moves with six pieces only.
Christmas Puzzle 10 – Text puzzle
Can eight white pieces (K, Q, R, R, B, B, N, N) guard all 64 squares of the chessboard?
Solution: They can't if the bishops are of opposite colour. They can, if you allow both bishops to occupy the same coloured squares:

December 29th, 2025
Christmas Puzzle 11 – Retro
Werner Keym, Landeszeitung für die Lüneburger Heide 2011

Add one piece to each diagram to construct a mate
Solution 1: With the white queen on f1 the position is indeed a mate. But from which square could the queen have come? But you cannot have the black king mated from any other square, or by any other piece. So: it must be the white king that is mated, with a black queen on e2!
Solution 2: With the position flipped 180°, a white queen on c8 mates the black king and is legal. It could have come with the move c7-c8Q#! And in the second position a black queen or any other piece cannot mate the white king.
Christmas Puzzle 12 – Retro
Werner Keym, Stuttgarter Zeitung 2020

Mate in two moves.
Solution 1: In the first diagram Black could not have made the last move, so the solution is not 1.Rc4 K×d3 2.Rf3#. It must be Black to move, and he has to play ...Kxd4, and White mates in two moves with 1.Nf4 Ke3/Ke5 2.Bc5#/Bc3#
Solution 2: In the second flipped diagram there is, in fact, a possible last black move. Let us start from the following diagram
White has just given check with the bishop. There follows d7-d5 c5xd6 e.p. K×d6 (you can enter these moves on the diagram), and now we have White to move, with the solution 1.Rf5! K×e6 2.Rc6#. There is no reason to assume that it is Black to move with the solution 1.K×e5? Sc5 2.Kd4/Kd6 2.Bf6#/Bf4#
Christmas Puzzle 13 – Text puzzle
Puzzle: Place a white pawn anywhere on an empty board. What is the least number of moves you need to pass through (not necessarily land on) all nine squares in the a1-c1-c3-a3 area on the bottom left? From where must the pawn start? There is only one solution.
Five moves. The white pawn must be placed on the square h7. After the move h7-h8Q the promoted queen can pass through all nine squares on the bottom left in four moves:

The moves are 1.h8Q-a1-a4-d1-b1 (or, of course, h8Q-a1-d1-a4-a2)