The chess program P.ConNerS

Some data about P.ConNerS

• Program author: Ulf Lorenz, at that time member of the research group of Prof. Dr. B. Monien at the University of Paderborn.
• P.ConNerS was a pure test vehicle for experiments in the fields of selective game tree search and parallel computing. There was no commercial interests.
• P.ConNerS stands for 'Parallel Controlled Conspiracy Number Search'. Thus, the tournament victory was highly interesting from a research perspective, as well: P.ConNerS used a non-conventional, non-alphabeta search algorithm. The search algorithm tries not only to maximize the search depth, but also tries to guarantee that even when one leaf-value changes, the result stays the same. A conspiracy 2 search may be interpreted as a special, global arrangement of a lot of so called singular extensions. As a result, it domain-independently searches highly selective and irregular game trees. The program is written in C.
• P.ConNerS ran in parallel and got its playing strength out of a workstation cluster, which consisted of 160 Pentium II, 450 Mhz processors. Those were connected with a new European interconnection network, the so called SCI network. On that machine P.ConNerS examined between 3.5 and 5.0 Mnds/sec. On the 160 processors it achieved a speedup of about 50.