What was the Last Move?

It is clear that the more the list is filled, the more difficult it gets to find new positions or to improve existing ones.

To give you some appetizer, I've included some of my own positions with 13-15 pieces which I wasn't able to reduce to 12 or less pieces. Maybe one of you can do a better job with those?!

We now have:

161 records
52 records, where both last moves are of the same nature (these are called Type DD positions)
51 records with 12 or less pieces

missing DD-positions:

QxQ QxR QxB RxR PxR=Q

To keep the list a little bit shorter, the following abbreviations are used:

rml = Retros Mailing List,

feenschach 64 = feenschach, Heft 64/1983, p.29ff

Note, that the last move combinations are normalized for ordering purposes, i.e. even if White's last move was e.g. NxR, and Black's last move was K-, this is not listed as 'NxR/K-', but as 'K-/NxR'.
To be compatible with Andrew Buchanan's website (see below), the ordering used both within on move pair as well as between move pairs is the same as for Type A-C.

Thanks to the efforts of Andrew Buchanan you can also view this list in a nice graphical manner on Andrew's webpage http://www.geocities.com/anselan/TYPE-D/TYPE-D.html (Andrew also presents lists of records of other last move types, as well as some other interesting retro questions - especially about 'Dead Reckoning', so you should visit his website http://www.geocities.com/anselan/chess.html in any case.)

In the following list, entries marked red, indicate new records since 09.05.2007.

Mario Richter

Record List

Type D: One solution assuming White has the move, another one solution assuming Black has the move