Blockade of Stop
Blockade of Stop,
the obstruction of the stop square of a pawn mechanically prevents its advancement. While two opponent pawns head on head on the same file, a pawn ram, mutually block each other, the blockade of stop usually refers to pieces.
The more general term Blockade also refers to a chess tactics where a decoy sacrifice is conducted to decisively reduce the mobility of pieces or king as start of a combination.
Most notably in passed pawn evaluation , the blockade of stop reduces the bonus by up to one rank less advanced or even more. Programs may further scale the blockade of stop penalty depending on piece type and color, where an opponent bishop, followed by opponent king and knight are most effective to blockade the stop. A rook, either an own or opponent one, might already considered by the Tarrasch rule, despite that rule also covers tele stops.
During the opening, some programs apply penalties for stop square obstruction by own pieces of none developed center pawns.
- Blockage Detection
- Connected Passed Pawns
- Control of Stop and Telestop
- Passed Pawn
- Pawn Rams (Bitboards)
- Tarrasch Rule
- Aron Nimzowitsch (1925). Die Blockade. Bernhard Kagan, Berlin, English version by Philip Hereford (1929). The Blockade. German online version edited by Wilfried Krebbers, nimzowitsch.net
- Aron Nimzowitsch (1925,1927). Mein System. Bernhard Kagan, Berlin, English version by Philip Hereford (1930). My System. Harcourt, Brace and Company, German online version edited by Wilfried Krebbers, nimzowitsch.net 
- Lyudmil Tsvetkov (2010, 2012). Little Chess Evaluation Compendium. File:LittleChessEvaluationCompendium.pdf