Differences

This shows you the differences between two versions of the page.

--- chess:programming:polyglot_book_format:enpassant [2022/01/11 13:57] – created peter
+++ chess:programming:polyglot_book_format:enpassant [2022/01/11 14:02] (current) – peter
@@ Line 1: / Line 1: @@
 ====== Chess - Programming - Polyglot Book Format - Enpassant ======
-**Enpassant** is part of the key.
+**Enpassant** is part of the [[Chess:Programming:Polyglot Book Format:Key|Key]]
-If the opponent has performed a double pawn push and there is now a pawn next to it belonging to the player to move then "enpassant" is the entry from RandomEnPassant whose offset is the file of the pushed pawn (counted from 0(=a) to 7(=h)).
+It is the exclusive or of entries from the **RANDOM_ENPASSANT** sub-array.
-If this does not apply then enpassant=0.
+  * The offset is the file of the double-pushed pawn resulting in enpassant (counted from 0(=a) to 7(=h)).
-**NOTE:**  This is different from the FEN standard.
+<WRAP info>
+**NOTE:**  If this does not apply then enpassant=0.
+This is different from the FEN standard.
   * In the FEN standard the presence of an "enpassant target square" after a double pawn push is unconditional.
+  * It is irrelevant if the potential enpassant capturing move is legal or not.
+    * Examples where it would not be legal are when the capturing pawn is pinned or when the double pawn push was a discovered check.
-Also note that it is irrelevant if the potential en passant capturing move is legal or not (examples where it would not be legal are when the capturing pawn is pinned or when the double pawn push was a discovered check).
+</WRAP>