The 4th World Microcomputer Chess Championships were held at Glasgow in September 1984. Nineteen programs took part and first place was shared between the Psion program of Richard Lang, the Princhess program of Ulf Rathsman, Spracklens latest Fidelity version and a program called Mephisto Exclusive S. In fact three versions of Elmar Henne and Thomas Nitsche’s Mephisto program competed on machines equipped with 68000 processors running at 12 MHz. Mephisto had both numerical and hardware advantages over their main opposition.
However Henne and Nitsche’s program stood out from the others. It incorporated a highly selective search algorithm, which means the program relied on looking at a relatively small number of lines of play using a greater depth of search and chess knowledge to evaluate each position. A more human approach to finding the next move. Mephisto III-S Glasgow is said to evaluate only around 4 nodes per second compared with some brute force searches which are a hundred times faster on comparable hardware.
The way the Mephisto III-S Glasgow plays chess still attracts interest and praise from chess computer enthusiasts, particularly those in Germany. However with the Exclusive S board this machine was priced at 2999 DM (about £1350), which was expensive for a machine now rated at only 1630 Elo. Despite the WMCC result the Fidelity Elite Glasgow was rated about 100 Elo higher and within a year the III-S was left well behind by the Mephisto Amsterdam modules currently rated at 1927 and released at a price of 1200 DM. In short the Mephisto III-S was too expensive.
Which all goes to make it a rare, sought after and still technically interesting chess computer today.