Why did the rook and pawn get divorced? After the pawn’s promotion, the pawn decided it was a queen. How did the rook prevent the divorce?
In this week’s position black needs its king to escort its pawn to the promotion square on e8. Simply advancing the pawn with only the support of its rook is insufficient. White thwarts the pawn’s advance by putting its rook in position to check black’s king from behind. Thus, white’s drawing moves are rook to b7 or b8. The b6 square is too close to white’s king and more precise play is needed for the draw.
After rook to b8, the black king may move to f3. White’s rook checks the king from f8 (see next diagram).
The black king needs to be near its pawn, so if it moves to g3, then white’s rook attacks the pawn from e8, forcing the black king back to the “f” file. Hence the black king circles around to the other side of the pawn via e4 to d4 or d3 as the white rook continues to deliver checks. After being checked, the black king can move to c3 to try and change the timing but the rook, like when king moved to g3, now moves behind the pawn (see next diagram).
The black king is forced to guard the pawn and the checking repeats itself. Please note that if the black king advances down the board toward the white rook, the king will get too far away to protect the pawn.
This week’s position is a subset of the “Third-rank defense” or Philidor’s defense, named after the famous composer Francis Andre Philidor, whom many experts consider the best player of his time (late 18th century). Philidor and Benjamin Franklin were friends and Philidor often defeated Franklin in chess.
Reach Eric Morrow at ericmorrowlaw@gmail.com or (505) 327-7121.