# What do DTM, DTZ, DTC, DTR, DTZ50, and DTZR mean?

I need help clarifying the abbreviations and acronyms used in endgame tablebases. Just what do DTM, DTZ, DTC, DTR, DTZ50, DTZR mean?

In various endgame tablebases, the terms mean as follows:

Depth to Mate. For each position that is represented, 'DTM' indicates the theoretical value, and the number of winner's moves to 'Mate' if won/lost - assuming that the winner is minimizing and the loser is maximizing DTM.

DTC Depth to Conversion 'Conversion' is the changing of the force on the board, by capture and/or Pawn-conversion. For each position that is represented, 'DTC' indicates the theoretical value, and the number of winner's moves to the goal of 'Won Conversion' if won/lost - assuming that the winner is minimizing and the loser is maximizing DTC.

DTZ Depth to Zeroing (of the ply count) The ply-count is zeroed if and only if a Pawn is pushed or a capture is made. For each position that is represented, 'DTZ' indicates the theoretical value, and the number of winner's moves to the goal of 'Win and ply-count zeroed' if won/lost - assuming that the winner is minimizing and the loser is maximizing DTZ.

DTZ50 Depth to Zeroing (of the ply count) in the context of the 50-Move Rule The DTC, DTM and DTZ metrics do not consider the current FIDE 50-move rule whereby a game in which no irreversible moves have been played for 100 plies can be claimed as a draw by the player 'on move'.

DTR Depth by the (k-move) Rule 'The Rule' referred to here is a notional set of k-move rules. For each position that is represented, 'DTR' indicates the theoretical value and, for won/lost positions, the least k for which DTZk is not draw - assuming that the winner is minimising and the loser is maximising DTR.

DTZR Depth to Zeroing move, give that DTR is being minimaxed If DTR = draw, then DTZR = draw. Otherwise, Otherwise DTRZR indicates the theoretical value, and the number of winner's moves to the zeroing of the ply count, given that the two sides are minimaxing first DTR and then DTZR.

DTZR would be used in conjunction with DTR to progress a deep win in the context of a k-move rule because DTR can remain unchanged over a sequence of moves.

• +2 :) Good question/answer. Even though you won't get the 15 extra points, you should still accept your own answer at some point since it is correct. Feb 18 '20 at 21:23
• Thanks. It says i have to wait two days to accept my own answer Feb 18 '20 at 21:39