En Passant

In yesterday's after school chess club, I presented a position and conclusion to a game I had played earlier in the day. In a discussion about a different game on social media this morning, I mentioned this game again. IM Cyrus Lakdawala pointed out some similarities between my game and Aronin -- Smyslov, Moscow 1951, inquiring whether Smyslov's idea might have given my opponent drawing chances. Curiously, both games featured an en passant capture. In Smyslov's game en passant produced the kingside pawn structure that would have resulted in my game had my opponent chosen not to capture en passant.

Black to move

This position is completely even. But, here, my opponent blundered.

32...Rd8??

With the move came a draw offer, not my opponent's first such offer. Just about any other move that keeps the rooks on the board is equal, but the pawn ending is completely winning for White. Before exchanging rooks, I spent 38 seconds (a long think in a ten minute game) contemplating the pawn ending. I saw that my king has a route behind Black's pawns.

The Black king, in contrast, cannot penetrate to my side. My pawns control all points of entry.

However, Black does have a pawn break with f5 that can alter the pawn structure. As it happens this was a critical resource in Smyslov's game.

Central to my plan of penetrating with my king is that I am able to create a passed pawn on the h-file. Lev Aronin also gained a passed h-pawn against Smyslov. I knew my opponent could prevent my h-pawn from becoming passed, but that allows my king to enter via a shorter route.

34.Rxd8 Kxd8 35.h4

Black to move

As I explained in the discussion with Cyrus, if I had not found a route for my king, I would have played 35.h3, forcing an exchange of pawns.

Playing the pawn two squares instead of one offers Black the choice of capturing it as if it had moved only one square, or letting me have a passed h-pawn. That is en passant (capturing the pawn in passing), the rules for which was part of my lesson in yesterday's chess club.

35...gxh3+

White to move

36.Kxh3 Ke7 37.Kg4 Ke6 38.Kg5 f6+ 39.Kg6 Ke7 40.g4 Ke6

White to move

The maneuvering for opposition and outflanking is vital in this position. It is not yet a technique this group of students knows well. Teaching them how to do so was not the object of the lesson. Rather, I simply wanted to show them the process and use another day to teach them how to do it. Learning the en passant rule was the most important lesson for many of the children.

41.c4 Ke7 42.c5

Securing the queenside was not necessary but having already thrown away a decisive advantage to reach an equal endgame, I was not willing to allow any complications.

42...Ke6 43.g5 fxg5 44.Kxg5 Kf7 45.Kf5 Ke7 46.Kxe5 Kf7 47.Kd6 Kf6

White to move

48.e5+ Kf7 49.Kd7 and Black resigned.

Aronin -- Smyslov, Moscow 1951 is the first ending in Vasily Smyslov: Endgame Virtuoso, trans. Ken Neat (1997).

White to move

45.g4

Smyslov writes that his opponent was sure of victory when he played this move.

45...hxg3

No, Aronin was not unfamiliar with en passant. Rather, he saw, correctly, that he could get a passed h-pawn.

46.fxg3 g4!

Smyslov writes, "A paradoxical decision, since the h-pawn becomes a passed pawn" (7).

47.h4

Black to move

Compare the kingside pawn structure here to my game after 35.h4

47...c5 48.Ke2 Kh7

This was the move that caught my eye while looking at Cyrus Lakdawala's analysis of Aronin -- Smyslov.

White to move

49.Kd3 Kh6 50.c3 a5 51.cxb4 axb4 1/2-1/2

Smyslov notes that 52.Kc4 is met by f5!

A key pawn break, mentioned above.

53.Kd3 f4 54.gxf4 exf4 55.Ke2 Kh5 56.e5 Kg6 and Black's king stops White's two passed pawns. Black's pawns are another matter.

Analysis Diagram

The discussion with Cyrus hinged on the differences on the queenside between my game and Smyslov's textbook demonstration of a drawing resource. Instead of capturing en passant, my opponent might have tried 35...Ke7

White to move

Play might have continued 36.Kf2 Kf6 37.Ke3 Kg7 38.Kd3 Kh6 39.Kc4

Cyrus pointed out, as did Smyslov, that Aronin could not play this move.

39...Kg6 40.Kc5

Black to move

Black can strike with 40...f5 or wait with Kh7.

40...f5 41.exf5 Kxf5

White to move

42.Kc4 is the only winning move.

Alternately 40.Kh7

White to move

White loses with 41.Kb6, which was part of my calculation when I opted to exchange rooks. However, 41.Kd6 wins. I would like to believe I would have found the correct move here had my opponent been enough of a student of Smyslov to put me to this test. Instead, by capturing en passant, I was given an easy finish. What might have been, on the other hand, is a source of chess pleasure