King & Pawn Endgames: Answer Time

The other day I presented this position and asked a couple of questions.

St. Amant - Staunton, Paris 1843 (m11)

After 43 Kc3-c2

What is the proper assessment of the position? How many acceptable plans does Black have?

The answers are that Black has a won position, and he has exactly ONE winning move. In fact, all moves other than 43...Kxd4 lose. Staunton chose to play 43...Ke4 and duly lost. I can only assume he originally intended to follow-up with 44... Kf3 and then promote his e-pawn. However, that plan does not work because of St. Amant's move, 44 Kd1, and now the White king will blockade the Black e-pawn, whilst Black has to run down White's d- and g- pawns, allowing White to easily win Black's queenside pawns. I don't know anything about the particulars of this game other than that Staunton was leading the match by the score of 8+, 1-, 1= prior to this game. Perhaps Mr. Staunton merely had a lapse.

But the winning line isn't 100% straightforward, either. Black still has to worry himself about that pesky g-pawn. How can he catch it and not let White clean up all of Black's pawns? The answer is that he can't. But that he doesn't have to, because White can be deflected from his own queenside pawns by the Black e-pawn, and that plus the unfortunate (for White) geometry between c4, e2 and g8, gives Black a winning position.

After 43...Kxd4 White's best is 44 Kd1 (If 44 g4, then Ke4, and Black will be able to round up the g-pawn and return in time to guard the e-pawn, and if Black tries breaking through on the queenside, Black's e-pawn queens far too quickly for White to get his pawns up the board):

 After 44 Kd1

44      ...     Kd3

45     g4      e2+

46    Ke1    Kc2!

 After 46 ... Kc2!

47    g5          

(47 Kxe2 transposes to the main line)

47      ...     Kxb2

48      g6     c3     

49      g7     c2     

         50      g8(Q)      c1(Q)+

51     Kxe2  Qc4+

After 51 Qc4+

And there's an unfortunate triangle for White. Another interesting fact is that all but one of Black's moves from 43 to 50 are only moves - anything other than the move given above loses. The one exception is that Black can play 44...c3 and still draw. These endings are precise!

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On a programming note, I hope to return to semi-regular blogging, at the very least. Soon we will have final news on the on-going Club Championship, and there may even be a game or two worth noting.