Christmas puzzles: Add-a-king, and take that back!

Problem specialists and older readers may be familiar with one or the other of the following problems, which we may have published before. But there are grandmasters who were not born at the time, so simply bear with us. 

Add-a-king

These twin problems are by the ever capricious T.R. Dawson, composed in 1927. Your task is on each diagram to add a white queen on a legal square and then stalemate Black in one move. But in doing so you will have to figure out why, in two diagrams that are perfect mirror images, the solutions are quite different.

It should be mentioned that Bengt Giöbel published a variation of Dawson's problem nineteen years later. In the above positions you are required to add a white queen, but this time to mate in one move. And of course the question remains: why are the solutions so dissimilar? And the answer to that is exactly the same as for the Dawson problems.

In this problem you are required to replace the white king on the board and then mate in two moves. If you find the solution and are a problem enthusiast, you can work out why each of the pieces is necessary for the problem to succeed.

Retractors: take that back!

The first position is a classic – it was composed 110 years ago! White takes back his last move and plays something different, mating instead in one move. The second position is just ten years old and requires that White takes back his previous move and instead mates in two moves. This problem has a nice little logical twist.

And finally a more recent retractor:

White takes back his previous move and instead mates in one 

The solutions to all of the problems of our Christmas gallery will be published on January 1st of the new year – which will hopefully be better than the dreadful 2020. To all our readers: stay safe and keep cheerful.