fix: remove "duplicated" board positions from Book.txt #39
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Motivation
The Book.txt seems to be agnostic to en-passant square. For example, the second entry in the book is
And it technically it should be
Because in openings, it's mostly impossible to take advantage of the en-passant square, it's a good trade-off to ignore it. That does make sense.
The Issue
There are two positions in the book that given the en-passant square is ignored are the same positions and duplicates of each other.
PR Changes
This PR updates Book.txt to remove those two "duplicate" positions .
Note
I found that they are duplicates when creating a json version of the openings and using a modified zobrist hash that does not consider the en-passant square. AFAIK those are the only two "duplicate" entries
It might be the case that maybe the non en-passant position needs to be removed, but given that the 2nd, 4th and other entries are not setting en-passant square in the fen notation, it seems to be a good option to remove the en-passant one .