# Stats

`gather_statistics` command allows gathering various statistics from a .bin or a .binpack file. The syntax is `gather_statistics (GROUP)* input_file FILENAME`. There can be many groups specified. Any statistic gatherer that belongs to at least one of the specified groups will be used.

Simplest usage: `stockfish.exe gather_statistics all input_file a.binpack`

Any name that doesn't designate an argument name or is not an argument will be interpreted as a group name.

## Parameters

`input_file` - the path to the .bin or .binpack input file to read

`max_count` - the maximum number of positions to process. Default: no limit.

## Groups

`all`

 - A special group designating all statistics gatherers available.

`position_count`

 - `struct PositionCounter` - the total number of positions in the file.


            reg.add<KingSquareCounter>("king", "king_square_count");

            reg.add<MoveFromCounter>("move", "move_from_count");
            reg.add<MoveToCounter>("move", "move_to_count");
            reg.add<MoveTypeCounter>("move", "move_type");
            reg.add<MovedPieceTypeCounter>("move", "moved_piece_type");

            reg.add<PieceCountCounter>("piece_count");

`king`, `king_square_count` - the number of times a king was on each square. Output is layed out as a chessboard, with the 8th rank being the topmost. Separate values for white and black kings.

`move`, `move_from_count` - same as `king_square_count` but for from_sq(move)

`move`, `move_to_count` - same as `king_square_count` but for to_sq(move)

`move`, `move_type` - the number of moves with each type. Includes normal, captures, castling, promotions, enpassant. The groups are not disjoint.

`move`, `moved_piece_type` - the number of times a piece of each type was moved

`piece_count` - the histogram of the number of pieces on the board