The ChessPositionRanking project, with help from the Texel chess engine author, tries to prove random positions (that are not obviously illegal) legal by constr

The ChessPositionRanking project, with help from the Texel chess engine author, tries to prove random positions (that are not obviously illegal) legal by constructing a game ending in the position. If that fails it tries to prove the position illegal. This now works for over 99.99% of randomly generated positions, so one can feed the legal game record found for random legal positions.