From January 9-11, 1998, the two German amateur chess programs DARKTHOUGHT and XXXX-II (both participants of the last three World Microcomputer Chess Championships) played a uniform platform match at our institute (IPD, University of Karlsruhe, Germany). Two 500MHz DEC Alpha-21164a PC164 workstations with 256MB RAM each and Digital Unix 4.0b system software as provided by Digital Equipment Corp. under external technology research contract DE-0032-97 served as the uniform platform hosts.
Initially, Martin Zentner (the author of XXXX-II) proved that his C++ program is very well designed. With a little help by our DARKTHOUGHT team he ported XXXX-II to the 64-bit DEC Unix operating system in a couple of hours. Although this was the first time for XXXX-II to use a true 64-bit environment it performed flawlessly during the whole match. Using the DEC Unix C++ compiler with heavy optimizations enabled, XXXX-II ran roughly 10% faster on the 500MHz DEC Alpha-21164a than on a 300MHz Pentium-II under Windows/NT 4.0 when being compiled by the latest version of Microsoft Visual C++.
The match itself consisted of 9 games at tournament time controls (30 moves in 60 minutes, then repeated 40 moves in 60 minutes). The first five games were played from the so-called ``Nunn Positions #4 and #5'' with opening books disabled. As intended by GM John Nunn, both programs felt about equal in the starting positions. DARKTHOUGHT won all these five games although it accidentally played Black with a tempo less than required in the very first game. With enabled opening books the games would have progressed completely different because both programs found the starting positions in their books. Furthermore, the Nunn game setup seems to favor the faster program (in this case DARKTHOUGHT) as the first 10-12 common theory moves do not contribute to the time control.
The last four games were normal tournament games with opening books enabled. Here, it quickly became obvious that XXXX-II features a much better opening library than DARKTHOUGHT which had to fight hard for its three wins and just a single loss in the normal games. The overall score of the match: DARKTHOUGHT = 8 points, XXXX-II = 1 point.