Central Rook vs Side Pawn


Central Rook vs Side Pawn is an older joseki for a Central Rook position by White played against a Static Rook position played by Black that captures White's side pawn on 34.
It was seen up until the 1950s-1980s but is now no longer used by professional players as the judgment of the position then appeared to strongly favor Black.
An example of this opening occurred in the meijin match between Masao Tsukada and Yoshio Kimura on June 6, 1947.

Development

1. P-76 P-34, 2. P-26 P-54, 3. P-25. The opening starts with a position that with both players' bishop diagonals open looks similar to White's Cheerful Central Rook. Both bishop diagonals are open, Black has chosen a Static Rook position, and White has pushed their central pawn.
3...P-55. However, on the fifth move, joseki diverges from Cheerful Central Rook. White's central pawn is pushed to the middle rank 5 closing the bishop diagonal and preventing a bishop trade.
.
4. P-24 Px24, Rx24. Since the bishop diagonal is closed, Black can trade pawns on the second file.
Subsequently, Black captures White's side pawn while White swings their rook to the central file.
After Black moves their rook back to the second file, White attacks on the central file and then trades bishops.