[Event "K+R+P vs K+R+2P"] [Site "www.masterchessopen.com"] [Date "1954.01.01"] [Round "0"] [White "Alexander"] [Black "Unzicker"] [Result "0-1"] [EventType "game"] [EventCountry "NED"] [FEN "8/r7/5kp1/8/p5P1/R4K2/8/8 b - - 0 1"] { The main principle of rook activity was explained by Tarrasch: the rook is best posted behind pawns, whether one's own or the opponent's. This rule is especially valid for the passed pawn. If posted behind ones' own passed pawn, the rook adds power to its advance, and forces the opponent to block the pawn, thus making his own pieces passive. An instructive example of Tarrasch's rule is shown here. Compare the capabilities of the two rooks, especially the white rook's unsavory role. White's rook has no useful move, because if, say, 1.Re3 or 1.Ra1, then Black's passed pawn will move ahead. } 1...Ke5 2.Ke3 g5! { Remember this position, since it introduces us to another element of endgame strategy. White is to move, but any move by his pieces would lead to positional or material loss. For example, if 3.Kf3, then 2...Kd4 and Black's king moves to support his passed pawn, while if 3.Kd3 Kf4, and White loses the g-pawn. The alternative is to move the rook, but after 3.Ra2 a3, White again is forced to make an unfavorable move. This situation is called zugzwang (German for "move compulsion"), and is often encountered when exploiting material or positional advantage in rook-and-pawn endgames. Of course, White could be tricky with 3.Ra1 a3 4.Ra2, trying to avoid the zugzwang situation. But then the waiting move 4...Ra8 (or to any other square on the a-file) once again puts the opponent in zugzwang. This typical "transfer of the move" is well worth remembering. The game ended as follows: } 3.Kf3 (3.Ra2 a3) (3.Ra1 a3 4.Ra2 Ra8) 3...Kd4 4.Kf2 Kc4 5.Ke2 Kb4 6.Ra1 a3 7.Kd3 a2 8.Kc2 Ka3 {#R} 0-1