from the booklet Kings Move - Welcome to the 1989 AGT World Computer Chess Championship 
BP spends 95% of its time in evaluation and the rest on move generation and search. Because of this, it must do a selective search, to prune forward at every level of the search tree.
BP, in an n-ply iterative-deepening process, does some forward pruning even at ply 1. There are good, interesting, and bad moves. Good ones appear to win material. Interesting ones exchange material, or are the best move in a previous iteration. Bad moves appear to lose material. There is also consideration given to tactical conditions, such as whether there is a piece under attack or if the machine is retreating from check. At ply 1 during early iterations all possible moves are examined. At ply 1 and 2 the good and interesting moves are fully explored, but the bad moves are pruned at n-2. Near the bottom of the tree some "serious pruning" is enacted. BP has a 65K position table and would like to make this larger for endgames. It runs on a 33 MHz 486 processor. The iterative deepening goes in steps: 2,4, ... n-2, n. When they announce a 6-ply analysis, it is a pseudo-6 ply of full width. They examine approximately 1600 nodes/sec. Part of the BP philosophy is expressed: "If we prune on a even ply, and omit a good move, it is a shame. If we prune on an odd ply and omit a good move, it is a disaster."
BP played five ACM North American Computer Chess Championships, the ACM 1987, ACM 1988, ACM 1989, ACM 1991 and ACM 1993, as well the WCCC 1989 in Edmonton, Alberta, Canada  operated by Kevin O’Connell. In 1991, BP played the Illinois Open, where it became runner-up with a win versus GM Dmitry Gurevich .
[Event "WCCC 1989"] [Site "Edmonton, Canada"] [Date "1989.05.28"] [Round "2"] [White "Mulder BP"] [Black "Pandix"] [Result "1-0"] 1.e4 e5 2.f4 f5 3.exf5 Qh4+ 4.g3 Qe7 5.fxe5 Qxe5+ 6.Qe2 Nc6 7.d4 Qxe2+ 8.Nxe2 d5 9.Bh3 Bd6 10.Nbc3 Nge7 11.Bg5 Nxf5 12.O-O-O Nfxd4 13.Nxd4 Bxh3 14.Rhe1+ Kf7 15.Ndb5 d4 16.Nxd6+ cxd6 17.Nb5 Kg6 18.Bf4 Bg4 19.Rd3 Rae8 20.Rxe8 Rxe8 21.Nxd4 Nxd4 22.Rxd4 Re1+ 23.Kd2 Re2+ 24.Kc3 Rxh2 25.Rxd6+ Kf7 26.Rd2 Rxd2 27.Kxd2 b5 28.b3 h5 29.c4 bxc4 30.bxc4 Be6 31.Kd3 g6 32.a4 Bd7 33.a5 a6 34.Kd4 Kf6 35.Bc7 g5 36.Bd8+ Kf5 37.c5 Bc6 38.Be7 Kg4 39.Ke5 h4 40.gxh4 gxh4 41.Ke6 h3 42.Bd6 Kf3 43.Be5 Kg2 44.Kd6 Bf3 45.c6 h2 46.Bxh2 Kxh2 47.Kd7 Bg4+ 48.Kd8 Bf3 49.c7 Bg4 50.c8=Q Bxc8 51.Kxc8 Kg3 52.Kb7 1-0
Illinois Open 1991
[Event "Illinois Open"] [Site "Rosemont, IL"] [Date "1991.??.??"] [Round "3"] [White "BP"] [Black "Dmitry Gurevich"] [Result "1-0"] 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.Nxc6 bxc6 8.e5 Nd5 9.Nxd5 cxd5 10.Qxd5 Rb8 11.O-O-O Qc7 12.f4 O-O 13.b3 Rb6 14.Bxb6 axb6 15.Bc4 Qa7 16.a4 e6 17.Qd6 f6 18.exf6 Bxf6 19.Rhe1 Qa5 20.Re3 Bg7 21.Bb5 Qa8 22.g3 Rf7 23.Qxb6 Bf8 24.Qd8 Kg7 25.Rxd7 Rxd7 26.Bxd7 Ba3+ 27.Kd2 Qd5+ 28.Rd3 Qg2+ 29.Kc3 Qe4 30.Qb6 Qe1+ 31.Rd2 Be7 32.Bxc8 Bf6+ 33.Kd3 Qf1+ 34.Ke3 Qe1+ 35.Re2 Qc3+ 36.Ke4 Qxc8 37.c4 Qa8+ 38.Kd3 Qf3+ 39.Qe3 Qf1 40.Kc2 Qa1 41.Rd2 Qb2+ 42.Kd1 Qa1+ 43.Ke2 Qh1 44.Rd7+ Kh6 45.h4 Qg2+ 46.Ke1 Qh1+ 47.Kf2 Qh2+ 48.Kf3 Qh1+ 49.Kg4 1-0
- Photo from Dmitry Gurevich (1991). On The Road. Illinois Chess Bulletin, pdf » Illinois Open 1991
- The ACM's Eighteenth North American Computer Chess Championship from The Computer History Museum
- Kings Move - Welcome to the 1989 AGT World Computer Chess Championship. Edmonton, Alberta, Canada, Courtesy of Peter Jennings, from The Computer History Museum
- Garth Courtois Jr. (1991). Where is Computer Chess Going? ICCA Journal, Vol. 14, No. 4
- Mulder BP's ICGA Tournaments
- Ken Marshall (1991). Andrew Karklins Wins Illinois Open - GM Gurevich Upset By Computer Program Bp'*. Illinois Chess Bulletin, pdf
- Edmonton 1989 - Chess - Round 2 - Game 10 (ICGA Tournaments)
- Dmitry Gurevich (1991). On The Road. Illinois Chess Bulletin, pdf