Requires Java

This web page allows you to view the proof that checkers is a draw. Use the interface to play through the analysis and see Chinook's verdicts. To play a move, either:

a) Make a move on the board by clicking on the appropriate piece and then clicking on the destination square, or
b) Click on the move on the right-hand window pane. Note that there may be a pause before the move registers.

To undo a move, use the "Back" button at the bottom of the window.

As you play through moves, the right-hand-side window pane displays the proof results. Associated with a move is a result:

W: This position is a win.
D: This position is a draw.
L: This position is a loss.
D or W: This position is either a draw or a win (i.e., it has been proven not to be a loss).
L or D: This position is either a draw or a loss (i.e., it has been proven not to be a win).
leaf node: A small search (using the endgame databases) was able to prove the result of this node.
not in tree: The prover did not have to analyze this position.
unresolved: The prover examined this move but did not need to prove the value. Some of the moves from this position may include proven results.

Trouble Shooting

Java applet will not load

Yahoo! has an excellent help for this.
http://help.yahoo.com/help/au/games/games-09.html

java.lang.ClassFormatError: Bad major version number
at java.lang.ClassLoader.defineClass(ClassLoader.java:250)

You are running an older version of java.

Solution:
For Windows / Linux / Solaris users download and install the Java
Virtual Machine:
http://java.sun.com/getjava/download.html

For Mac OS X you can get information about downloading:
http://www.apple.com/macosx/features/java/

Java applet loads but I only see a gray background