Combining Knowledge and Search to Solve Single-Suit Bridge

Abstract

In problem solving, it is often important not only to nd a solution but also to be able to explain it. We use the game of Bridge to illustrate how tactics, which formalise domain-specic expertise, can be used for both these tasks. Our Bridge tactics constrain search to the point where optimal strategies can quickly be identified, and also provide the key to explaining these strategies in human-understandable terms. We demonstrate this using a canonical set of single-suit Bridge problems from a denitive expert text. Finesse `solves' these problems in the technical sense that, in addition to always nding optimal solutions (and revealing a 3% error rate in the expert answers), it also explains each solution in simple, clear English text.