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2008: The first WinBoard version. The engine is pretty much as it was in 1999, except now it is a 32-bit program instead of a 16-bit one. A few additions to the position evaluation code: pawn balance, square of the pawn, passed pawns, backward pawns... Plus some outlandish concepts such as piece mobility (!!!). Estimated playing strength: 2,120 Elo points (CCRL).

2009: A separate function to handle quiescence search. (Previously, one function handled both the full-width and quiescence searches, which made futility pruning a bit awkward.) This, plus a bug fix elsewhere in the search code increase WAXMAN's playing strength by 130 Elo points.

2010: Better move ordering with internal iterative deepening, worth about 60 Elo points. (New rating: 2,300+)

2013: Mildly selective search using late-move reductions and history pruning. Static exchange evaluation in quiescence search to weed out losing captures without actually searching them. No Elo gain at regular time limits, but WAXMAN's blitz rating is up!

2014: More aggressive LMR. Additional safeguards against reducing the wrong moves. Elo gain: 75 points. Support for WinBoard hint and analysis mode.

2016: Better time management in games with conventional time limits.

2017: Finally got around to implementing tapered evaluation properly: game stage now computed in every evaluation instead of just once per search. (Somewhat slower, but probably worth it, as the hash table doesn't have to be cleared between game stages...)
©1990-2017 Ivan Bacigal