# How does null move pruning work?

## How does null move pruning work?

also called Null Move Heuristic (NMH), is a method based on the Null Move Observation to reduce the search space by trying a “null” or “passing” move, then seeing if the score of the subtree search is still high enough to cause a beta cutoff.

**How do you implement null moving pruning?**

Thus, the best way to apply null-move pruning is by conducting a minimal-window null-move search around the current upper bound β, since such a search will require a reduced search effort to determine a cutoff. A typical null-move pruning implementation is given by the pseudo-code of Figure 1.

### What is null move in chess?

Often a null move is a placeholder in a pgn file to attach comments to regarding a position. It is denoted by “–” in PGN notation and internally represents a move by the king to it’s own square. As such it is an illegal move but as a vehicle for annotation it is extremely useful.

**What is meant by heuristic algorithm?**

A heuristic algorithm is one that is designed to solve a problem in a faster and more efficient fashion than traditional methods by sacrificing optimality, accuracy, precision, or completeness for speed. Heuristic algorithms often times used to solve NP-complete problems, a class of decision problems.

#### What is heuristic function?

Definition. A heuristic function (algorithm) or simply a heuristic is a shortcut to solving a problem when there are no exact solutions for it or the time to obtain the solution is too long.

**What is null in games?**

In game theory, a null move or pass is a decision by a player to not make a move when it is that player’s turn to move. Even though null moves are against the rules of many games, they are often useful to consider when analyzing these games.

## Which node will be pruned first?

Following are some rules to find good ordering in alpha-beta pruning: Occur the best move from the shallowest node. Order the nodes in the tree such that the best nodes are checked first. Use domain knowledge while finding the best move.

**What is an example of A heuristic?**

Heuristics can be thought of as general cognitive frameworks humans rely on regularly to quickly reach a solution. For example, if a student needed to decide what subject she will study at university, her intuition will likely be drawn toward the path that she envisions most satisfying, practical and interesting.