# What is alpha and beta in alpha-beta pruning method?

## What is alpha and beta in alpha-beta pruning method?

The two-parameter can be defined as: Alpha: The best (highest-value) choice we have found so far at any point along the path of Maximizer. The initial value of alpha is -∞. Beta: The best (lowest-value) choice we have found so far at any point along the path of Minimizer.

What is the difference between minimax and alpha-beta pruning?

Alpha-beta pruning is a procedure to reduce the amount of computation and searching during minimax. Minimax is a two-pass search, one pass is used to assign heuristic values to the nodes at the ply depth and the second is used to propagate the values up the tree. Alpha-beta search proceeds in a depth-first fashion.

### What is the condition for pruning in alpha-beta pruning?

The main condition which required for alpha-beta pruning is: α>=β Key points about alpha-beta pruning: o The Max player will only update the value of alpha. o The Min player will only update the value of beta. o While backtracking the tree, the node values will be passed to upper nodes instead of.

How does alpha beta pruning work in minimax?

If we apply alpha-beta pruning to a standard minimax algorithm, it returns the same move as the standard one, but it removes (prunes) all the nodes that are possibly not affecting the final decision. Let us understand the intuition behind this first and then we will formalize the algorithm.

## How to prune the minimax algorithm pseudo code?

We know that pruning happens only in the above stated two cases. So the only modifications we need to make to our existing Minimax algorithm pseudo-code is that, Add the parameters alpha and beta to the procedure. Add the conditions to update alpha and beta. Add conditions for pruning.

Which is pseudo-code for minimax search with alpha beta?

This is pseudo-code for minimax search with alpha-beta pruning, or simply alpha-beta search. We can verify that it works as intended by checking what it does on the example tree above. Each node is shown with the [min,max] range that minimax is invoked with.

### Why is alpha beta pruning algorithm called worst ordering?

Worst ordering: In some cases, alpha-beta pruning algorithm does not prune any of the leaves of the tree, and works exactly as minimax algorithm. In this case, it also consumes more time because of alpha-beta factors, such a move of pruning is called worst ordering.