A number of terminals are offered to the board evaluation function. Although more advanced terminals are given to provide access to individual squares (see Symmetric Evaluation), these terminals are given to increase the speed of determining a good evaluation tree. Presumably, the algorithm would have been able to approximate such terminals, given enough time. The idea here was to create an evaluation function with the best performance overall.

The basic evaluation terminals are:

• white: The number of white pieces on the board at this time.
• black: The number of black pieces on the board at this time.
• empty: The number of empty squares on the board at this time.
• random: A random number generator to add some variability to the game.
• 10: The number 10 itself, used to weigh other terminals or tree branches.

Additional terminals are provided for evaluating piece mobility in relation to the game's progress. These are covered under the Mobility section.

Example

The following board position returns the following scores for the terminals:

• white: 4
• black: 1
• empty: 59
• random: A number between 0 and 10

Performance

These terminals alone were not sufficient to beat Edgar. This is natural: basic strategy demands an understanding of corners and edges play to maximize control over the board. Without access to such information, a successful Othello player is not possible.