1) Positions are as close to the root position as possible to calculate the maximum Elo difference between 2 or more engine. Alternatively, if you use much deeper books, the ratings will be more compressed. My aim was to avoid the latter.
2) All positions differ in at least 6 ranks so that
a) there are no straightforward or likely transpositions and
b) to maintain some variety
3) All position evaluate between -50 and 50 centipawns and no position has an "obvious" first move choice.
All positions are from the ICCF 28 World Championship Semi-Finals:
http://dl.dropbox.com/u/11904592/WC28Semifinals.pgn
The EPD suite is here:
http://dl.dropbox.com/u/11904592/mpd_suite_mw.epd
