From Chessprogramming wiki
Jump to: navigation, search

Home * Engines * Freedom

a chess program by Nils Barricelli. It participated at the First World Computer Chess Championship 1974 in Stockholm, running on a CDC Cyber 74. It lost versus the strong CHAOS and Ribbit in round 1 and 2 respectively, and had a lucky draw from Tell.

Barricelli, at that time affiliated with the Oslo University [2], had already experience in chess programming for his Symbioorganisms experiments at University of Manchester in 1962, where Alex Bell worked for him and wrote his first legal-move generator. Freedom's evaluation was primary based on the ratio of own and opponents mobility aka number of legal moves.


Tony Marsland mentioned Freedom, Papa and other programs participating the WCCC 1974 in his handwritten notes [3] on the Hayes and Levy book [4] :

Freedom and Papa both use mobility as their primary term in their evaluation functions. As with Wita, both use the ratio of computer's moves / opponent moves. Papa and Wita also multiply by the ratio of the squares controlled and Papa goes one step further and takes the logarithm of this product to form the "entropy" of the position. The true merit of this entropy over the product ratio was not made clear, but it does ensure that in extreme situations the evaluation remains more closely bounded. 

Freedom vs. CHAOS

WCCC 1974, round 1, Freedom - CHAOS [5]:

[Event "WCCC 1974"]
[Site "Stockholm, Sweden"]
[Date "1974.08.05"]
[Round "1"]
[White "Freedom"]
[Black "CHAOS"]
[Result "0-1"]

1.d4 Nf6 2.c4 e6 3.c5 d6 4.cxd6 Qxd6 5.Nc3 Nc6 6.e3 Bd7 7.Bb5 Be7 
8.Nh3 O-O 9.Kf1 e5 10.Bd2 exd4 11.exd4 Bxh3 12.gxh3 Nxd4 13.Bc4 Qc6 
14.Bd5 Nxd5 15.Nxd5 Qxd5 16.Rg1 Nf3 17.Rxg7+ Kh8 18.Ke2 Qe4+ 19.Kf1 
Kxg7 20.Bc3+ f6 21.Kg2 Nh4+ 22.Kf1 Qg2+ 23.Ke2 Qe4+ 24.Kf1 Qh1+ 
25.Ke2 Qf3+ 26.Kf1 Qxd1+ 27.Rxd1 Bd6 28.Rd5 Bxh2 0-1 

External Links

Chess Program


Klaus Doldinger, Johnny Griffin, Kristian Schulze, Brian Auger , Volker Kriegel, Alexis Korner, Wolfgang Schmid, Curt Cress, Pete York


Up one Level