Thread: Alpha-beta pruning example

Hi, I'm studying for a test and trying to practice with alpha beta pruining. I found this site that I can practice potentially both (minimax with and without alpha beta, it's an applet), but it doesn't show the pruning when I choose alpha-beta drop down option. I copied the image and attached here, I just want to make sure I am cutting off the proper sub-trees. Just want to make sure I'm applying alpha-beta pruning correctly.

Alpha_beta_prune_eg.jpg

**When would it not be any benefit to use alpha-beta, because I know when we have a huge tree (high depth), then we can improve the a factor of its square root so with branching factor: b, depth: d, O(b^d) becomes O(b^(d/2). But when would alpha-beta pruning actutally be an overhead?? Any heap appreciated.

Hyperlink to image above: http://www.javaprogrammingforums.com...a_prune_eg-jpg

EDIT: My mistake, the applet just darkens the pruned sub trees, so I was correct.

When would alpha-beta pruning be an overhead rather than reduce time for AI to make a move? Any help appreciated.