GNU Backgammon evaluation functionality is driven by 3 separate neural networks. The neural nets evaluates each position statically, and returns the outcome probabilities of the game at the given position. However, there are several different methods and techniques that an evaluation can use, and these can be adjusted. It's possible to set different levels of lookahead, it's possible to add noise to the evaluation, and each evaluation can be done cubeful or cubeless. All these setting together form a total evaluation setting. In GNU Backgammon there are several of these evaluations setting for each operation GNU Backgammon does.