Betsy - Chess Programming Wiki

Hurricane Betsy 1 Hurricane Betsy ¹

Hurricane Betsy in the Gulf of Mexico in September of 1965 as taken by the TIROS-8 weather satellite. Source: NOAA Photo Library, September 4, 1965↩︎

Betsy,
a WinBoard compatible chess engine by Landon Rabern, written in C with a little Assembly, released in September 2000 ¹. Originally written in Pascal with its own text interface it was rewritten in C using rotated bitboards. Betsy applies PVS with null move pruning, and various standard and some aggressive non-standard extensions and reductions. According to a former Arena site, Betsy was the first published chess engine able to play Chess960 ², and was therefore Arena partner engine.

Contents

Neural Networks

Quote by Landon Rabern ³

As a child, I was obsessed with machine intelligence. I coded a strong chess AI (codenamed Betsy) and experimented with using neural networks in Betsy, both for the static evaluation at leaf nodes and within the tree for pruning. The networks learned from self-play to get about as good as my hand-tuned functions (discounting the slowdown incurred by sigmoid evaluation). I concluded that to do better, I would need to use raw game state data instead of the set of features I preselected as network inputs; unfortunately, this was 2000 and I did not have nearly enough processing power to do so.

C# Port

As of 2014, Landon Rabern started to port Betsy to C#, available as open source engine under the MIT License at GitHub. All the major components of a chess engine are there, just not a tuned evaluation ⁴. The board class embeds an 8x8 board and the Bitboard board-definition, and implements rotated bitboards. The search is implemented using a derivation chain of classes, the abstract base Brain, TranspositionTableBrain (Transposition Table, Iterative Deepening), and the concrete BasicAlphaBetaBrain (Alpha-Beta), NullMoveBrain (Null Move Pruning) and MTDfBrain (MTD(f)) classes.

Forum Posts

Re: C or C++ for Chess Programming? by Landon Rabern, CCC, August 18, 2000
Betsy 5.0 is now winboard compatable by Landon Rabern, CCC, September 06, 2000
Betsy 5.26 by Landon Rabern, CCC, July 06, 2001
Re: FRC_TheBaron_101 Vs Fritz8 (Castling vs Not Castling rules) by Landon Rabern, CCC, June 24, 2003
Betsy in Arena by Mark Loftus, CCC, September 13, 2003
Betsy 6.5.1 by Landon Rabern by Norbert Raimund Leisner, CCC, August 21, 2008

External Links

Chess Engine

Misc

Watch on YouTube

References

Up one Level

Betsy from WBEC Ridderkerk (Internet Archive)↩︎
Der Chess960-Express ist nicht mehr aufzuhalten, Chess Tigers Training Center, July 20, 2005 (German)↩︎
landon rabern - about (2019)↩︎
GitHub - landon/Chess: Beginnings of a port of Betsy to C#↩︎