Branching factor

In computing, tree data structures, and game theory, the branching factor is the number of children at each node, the outdegree.

For example, in chess, if a "node" is considered to be a legal position, the average branching factor has been said to be about 35,[1][2] and a statistical analysis of over 2.5 million games revealed an average of 31.

[3] This means that, on average, a player has about 31 to 35 legal moves at their disposal at each turn.

[1] Higher branching factors make algorithms that follow every branch at every node, such as exhaustive brute force searches, computationally more expensive due to the exponentially increasing number of nodes, leading to combinatorial explosion.

The higher the branching factor, the faster this "explosion" occurs.