A Pig and a Fork

After executing an elementary tactic in a blitz game a few days ago, I started looking for training positions for my beginning students. A rook on the seventh (or second) rank is sometimes called a pig, perhaps because of its tendency to gobble up pawns. Sometimes a weak back rank that is not fatally weak--that is, there is no checkmate--can lead to a position where a rook becomes a pig with check that also attacks a pawn. This situation occurred in my game.

Black to move

26...Qd1+ 27.Qxd1+ Rxd1 28.Kf2 Rd2+

The fork

29.Ke3 Rxb2 30.Ra4 a5 31.Ra3 Rxh2

White to move

With a two pawn advantage, Black went on to win.

I used the Manoeuvres search tab in ChessBase to find some training positions with hopes that my students could learn to play similar positions easily. My search was not narrow enough and I had to go through a hundred games to find a few of the sort that I sought. But other tactics emerged in this batch of games as well, and I filed away several positions.

This position from Euwe,M. -- Kroone,G., Amsterdam 1919 is simple enough.

White to move

32.Rc8+ Kg7 33.Rc7+ Kg6 34.Rxb7

White has restored the material balance and has healthier pawns and an active king. The effort to create threats and counterplay led Black to reduce his own rook's mobility and White won. Whether White already has a clear advantage, however, is less clear. The ending may prove instructive for my students. In particular, it was from this position that Stockfish evaluated the game as going from an advantage for White to a decisive advantage.

Black to move

Black played 38...a2. The engine sees Black holding after 38...Ra2.

White more clearly gains a decisive advantage with the maneuver in Zukertort,J. -- Pitschel,K., Paris 1878. This game also featured a queen exchange to simplify matters, as in my game.

White to move

34.Rc8+ Kg7 (other moves lead to a quick checkmate and another elementary lesson for my students.

35.Qg3+Qxg3 36.Kxg3

Black to move

36...Rc1

And now the fork on the seventh. White won the rook ending easily, or so it seemed.

37.Rc7+ Kf6 38.Rxa7 Rxc2 39.Rd7 Rxc3+ 40.Kh4 e4

Black also has a passed pawn.

41.Rxd6+ Ke5

White to move

42.Rxb6?

White let Black back into the game, but nonetheless went on to win. The lessons from this point in the game are for another day.