The "perft" nodes-per-second performance (which everybody measures differently; I simply traverse the complete tree with the same move generator that is used in search, including some bookkeeping) is about 13000KNs on a 2.66GHz Core 2 Duo. The nodes-per-second of the actual search in the first Nunn position is now about 1070KNs (64-bit) and 790KNs (32-bit) on a 2.66GHz Core 2 Duo, and about 480KNs (32-bit) on a 3GHz Pentium IV processor (mainly because bitscans are much slower on this platform). In contrast v1.8 scored about, respectively, 570KNs (no difference for 32-bit and 64-bit) and 350KNs (32-bit) on these two platforms. After a few preliminary tournaments, playing strength of the new BikJump seems improved when running on a Core 2 Duo, and appears the same on the older Pentium IV processor.
Although I had really hoped for much more noticeable gains from switching to bitboards and revising the sources, I decided to release BikJump v2.0 to give it a wider exposure. The source code has become much cleaner, while occasionally the new version plays pretty decent chess. I am still hopeful, though a little less optimistic than before, to make more substantial improvements later.
Results of a Nunn test set run-the-gauntlet 4'+1'' tournament, 512MB cache, Nalimov endgame tablebases (complete 3,4,5-piece, some 6-piece), ponder on, on an Intel Core 2 Quad Q6700 2.66GHz, 8MB L2 Cache, 1066MHz FSB, 6GB RAM:
BikJump v2.0 (64-bit)
- Roce 0.0380 16.0 - 3.0 +15/-2/=2 84.21%
- Mediocre v0.332 13.0 - 7.0 +11/-5/=4 65.00%
- BikJump v1.8 (64-bit) 12.5 - 7.5 +10/-5/=5 62.50%
- Philou 2.0.0 12.5 - 7.5 +12/-7/=1 62.50%
- Monarch 1.7 11.5 - 7.5 +10/-6/=3 60.53%
- BikJump v2.0 (32-bit) 11.0 - 9.0 +5/-3/=12 55.00%
- ZCT0.3.2447 JA 6.5 - 13.5 +4/-11/=5 32.50%
- Twisted Logic 20080620 0.5 - 19.5 +0/-19/=1 2.50%
- Fritz 11 0.0 - 20.0 +0/-20/=0 0.00%