Bill

Bill was the first strong learning othello program, the inspiration for later, stronger ones. The addition of learning made it far stronger than its immediate ancestor, the program IAGO. Later programs like Logistello surpassed Bill in turn with more learning and less hand-tuning.

references

A pattern classification approach to evaluation function learning (1988, paywalled)
Kai-Fu Lee and Sanjoy Mahajan
Artificial Intelligence, volume 36, pp1-25.

The development of a world class othello program (1990, paywalled)
Kai-Fu Lee and Sanjoy Mahajan
Artificial Intelligence, volume 43, pp21-36.