Smother Checkmate

As I work my way slowly through Tal's Winning Chess Combinations (1979) by Mikhail Tal and Victor Khenkin, I am combing my databases for additional examples. In this way, I am building a database of exercises for personal training, teaching, and hopefully a revision of my pamphlet "A Checklist of Checkmates" with work of such quality that I can interest a legitimate publisher.

I posted a clever smother checkmate from Tal and Khenkin's book two days ago. Since then, I have played through all of the moves in every game published in Chess Informant that ended with checkmate by a knight. There are only 47 such games, although certainly smother checkmate threats led to resignation in many other cases.

I found one instance of a the textbook classic checkmate in five. There were also a few variations on the theme. Below are four checkmate exercises from games published in Informant.

White to move

From Timman -- Short, Tilburg 1990 Informant 50/120

White to move

From Peters -- Lombardy, Lone Pine 1977 Informant 24/296

Black to move

From Steingrimsson -- Arnason, Island 1990 Informant 50/578

White to move

From Jorczik -- Strunski, Deutschland 2010 Informant 109/227

Leave your answers in the comments below. I usually reply.