 Haworth has discussed two other metrics, namely "depth to zeroing-move" (DTZ) and "depth by the rule" (DTR). A zeroing-move is a move which resets the move count to zero under the fifty-move rule, i.e. mate, a capture, or a pawn move. These metrics support the fifty-move rule, but DTR tablebases have not yet been computed. As of April 1, 2013, 5- and 6-man DTZ tablebases have been generated by Ronald de Man; both tablebases and generation code are available for download.
