Yes and no. The classic Nalimov bases don't, at all (pure DTM). The Syzygy bases that are the most common now do, but in a kind of weird way (DTZ50); they try

Yes and no. The classic Nalimov bases don't, at all (pure DTM). The Syzygy bases that are the most common now do, but in a kind of weird way (DTZ50); they try to get to the next zeroing move (pawn push or piece capture) as soon as possible, which means they play optimally from a win/draw/loss perspective no matter what the 50-move counter is but appear to play super-strangely (e.g. they may sacrifice a queen and go into a super-tricky won ending, instead of finding a mate in five). Galen Huntington has made proper DTM50 bases (http://galen.metapath.org/egtb50/ http://galen.metapath.org/egtb50/), which basically treats each position as different depending on the DTZ counter, i.e. “kings on a1 and a8 and a queen on c4” is really 100 different positions depending on who is to move and what the DTZ counter is, where some of them may have different mate distances and/or different results. That will give the shortest possible mate _and_ always take the 50-move rule into account. But they are not public, much larger than the Syzygy bases and generally more of a research project. Any engine that uses tablebases in its search will generally end up playing pretty strangely on the “knowledge horizon”, even when using DTM50 bases, for the simple reason that they will be happy to reach anything the tablebase says is a win, by any means. (E.g., again, if you have 8 pieces and 7-man tablebases and you don't see any other way of mating, sacrificing your queen to get into a won 7-man ending will be your best move.)