Some years ago, Jon Kreuzer started work on a checker playing program as an experiment in developing game-tree searching code. The experiment was refined over time, and when a graphical-user interface (GUI) was added, Jon gave his program a logical name: GUI Checkers. (You can click on the screen-shot above for a much more detailed full-sized version.)

The nascent GUI Checkers got the attention of world-class checker programmer Martin Fierz (creator of CheckerBoard and the Cake series of engines), and Jon was inspired to invest additional effort to improve GUI's playing strength and features.

The result is before us today: GUI Checkers release 1.00, and it is most impressive.

We put GUI through its paces here at The Checker Maven, first running our standard test against Simple Checkers. GUI won easily, and we wondered just how far GUI might go. We next tested against Marujito 1.08a, which itself can defeat Simple Checkers. GUI won that encounter as well. So we kept pushing. We then ran GUI against the solid Class B engine Damas 99. (Class B engines easily defeat Simple Checkers and are quite strong, but short of world class.) The result was an interesting draw (click here for animation), played without error or missed opportunity on either side.

But we had a hunch, and so we played GUI against Nexus, the strong forerunner of the world-class Nemesis program. Amazingly, GUI won the encounter! Of course, one game doesn't tell the whole story, but the win was most impressive. Here's the situation, and we invite you to find the winning line before clicking on Read More for the solution and full game animation.

WHITE

BLACK
Black to Play and Win

GUI 1.00 is thus established as a top Class B entry. It doesn't beat KingsRow or Cake Manchester, but it certainly plays a very worthy game. GUI features a small opening book and a small endgame database, a really nice look and feel, and some serious-minded features such as FEN and PDN import and export.

Author Jon Kreuzer granted the The Checker Maven an interview, and we learned that while he has produced an extraordinary checker engine, he has a more general interest in board game programming, having started with an Othello playing program while at Cornell University, and also having a strong chess playing engine to his credit. He has a current interest in 3D programming, as evidenced at his web site, 3D Kingdoms.

In talking about GUI Checkers, Jon points out that the program is open source and is probably the strongest open source checker program to be found. He does not have ambitions to advance it to the world-class category, but nevertheless has additional ideas on how to make it stronger and add features. He's especially interested in improving the opening book.

GUI Checkers author Jon Kreuzer

We asked Jon if he ever thought checkers would be completely "solved." He thought that perhaps it might, and that could limit his interest in further checker programming, but held out hope for the rest of us: "I don't think it should affect games between people." Well said, Jon, and congratulations on your fine achievement with GUI Checkers!

(GUI Checkers can be obtained from the author's web site, and it's well worth your while to do so.)

Solution

The Black win is fairly straightforward at this point, and here is the line chosen by GUI Checkers:

9-13 26-22 1-5 23-19 8-11 24-20 11-15 19-16 5-9 16-12 14-18 Black Wins.

You can click here to see the full game in animated form, including the rather unexpected and atypcial blunder made by Nexus just prior to the diagrammed position.