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====== Chess - Programming - Polyglot Book Format - Move ======

A **Move** is encoded as a bit field:

^Bits^Description^
|0,1,2|The destination file.|
|3,4,5|The destination rank.|
|6,7,8|The source file.|
|9,10,11|The source rank.|
|12,13,14|Promotion piece.|

<WRAP info>
**NOTE:**  Bit 0 is the least significant bit.
</WRAP>


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===== Promotion Moves =====

A **Promoted Piece** is encoded as follows:

^ Promoted Piece  ^ Value  ^
| None            | 0      |
| Knight          | 1      |
| Bishop          | 2      |
| Rook            | 3      |
| Queen           | 4      |

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===== Castling Moves =====

Castling moves are represented unconventionally as follows:

^Color^Castle Side^Polygot Move^
|White|King-side Castle|e1h1|
|White|Queen-side Castle|e1a1|
|Black|King-side Castle|e8h8|
|Black|Queen-side Castle|e8a8|

<WRAP info>
**NOTE:**  It is technically possible that these moves are legal non-castling moves.
  * Therefore a program should verify that a Castle-move was actually valid.
    * For example, verify that there is really a king present on e1/e8.

</WRAP>

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