Step by Step: Alpha Beta Pruning
Why Stack Overflow recommends it
Stack Overflow users link it when explaining or debugging minimax with alpha-beta pruning, since the worked example shows how the bounds propagate and why pruning does not change the result.
Recommended by 3 people across 3 different months, 2013 to 2018.
What it is
A 14-minute lecture clip from UC Berkeley's CS188 Artificial Intelligence course (Spring 2013), taught by Prof. Pieter Abbeel. It walks through alpha-beta pruning on a worked game-tree example, showing how alpha and beta values are passed down and when branches get cut.
What people said
Recommends phil_20686 · 2014-06 · Stack Overflow · on “How to display Alpha Beta Pruning algorithm result?”
I think it is displaying the right result, see, for example, [this video] and watch how the alpha and beta are carried around. I think that the algorithm just doesn't quite do what you think it does.
Recommends Andrei-Marius Longhin · 2016-04 · Stack Overflow · on “How to speed up minimax algorithm in Java?”
I have sucessfully tested the following methods for improving minimax (used it to play Tic-Tac-Toe and Domineering): Alpha beta pruning [this video] - used a special variant of this type of pruning, in conjunction with Lazy evaluation [LINK] - basically instead of generating the whole tree I just generated an optimal move on each layer and kept Lazy holders for the other state-action pairs (applying the Lazy evaluation method, by making use of a supplier and calling it when a move different than the one I held was made). Heuristic pruning [LINK] - see the chapter on heuristics in that book. I basically only generated the first d branches of the tree and instead of having a deterministic outcome,
Recommends Jakub Licznerski · 2018-01 · Stack Overflow · on “How does pruning help when I will have to traverse complete graph to find the terminal states?”
You don't have to traverse the full graph as pruning will determine branches that will not give you a better solution for sure and "delete" them from graph. Here [this video] is the video which helped me understand the algo.
Cites sage88 · 2013-03 · Stack Overflow · on “Java Minimax Alpha-Beta Pruning Recursion Return”
I am trying to implement minimax with alpha-beta pruning for a checkers game in Java. My minimax algorithm works perfectly. My code runs with the alpha-beta code in place. Unfortunately, when I play 1000 games vs the standard minimax algorithm, the alpha-beta algorithm always comes out behind by 50 games or so. Since alpha-beta pruning should not be reducing the quality of the moves, just the time it takes to achieve them, something has to be wrong. However, I have taken out pen and paper and drawn hypothetical leaf node values and used my algorithm to predict whether it will calculate the correct best move, and there doesn't appear to be any logic errors. I used the tree from this video: Al