
23.4 Adapting HTN Planning for Bridge 521
Table 23.1 Game-tree size produced in bridge by a full game-tree search
and by the planning algorithm used for declarer play in Bridge Baron.
Brute-force search Bridge Baron
Worst case About 5. 6 × 10
44
leaf nodes About 305,000 leaf nodes
Average case About 2. 3 × 10
24
leaf nodes About 26,000 leaf nodes
player might pursue, rather than the number of different possible ways to play the
cards [495]. Because the number of sensible stratagems is usually much less than
the number of possible card plays, this approach generates game trees that are small
enough to be searched completely, as shown in Table 23.1.
23.4