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The **Type B Strategy**, proposed in 1949 by Claude Shannon in his groundbreaking publication //Programming a Computer for Playing Chess//, is a selective approach to search minimax trees considering only a subset of plausible moves in contrast to the brute-force Type A strategy.

=Quotes= from Shannon's //Programming a Computer for Playing Chess//:





code | 1 if any piece is attacked by a piece of lower value, g(P) =   /    or by more pieces then defences of if any check exists \   on a square controlled by opponent. | 0 otherwise. code

=Type B programs= Most early chess programms were Type B and used a selective **width** for a maximum amount of plausible moves to be tried. Bernstein used {7, 7, 7, 7}, later programs chose width dependent from depth, Kotok-McCarthy had {4, 3, 2, 2, 1, 1, 1, 1, 0, 0}, while Greenblatt's Mac Hack used {15, 15, 9, 9, 7, ...}, and CHAOS carried out a selective search with iterative widening. With the advent of brute-force alpha-beta, and programs like Tech, Kaissa and Chess 4.5 in the early 70s, the era of the former dominating Type B programs drew to a close. Today most programs are closer to Type A, but have some characteristics of a Type B due to selectivity.

> include component="pageList" hideInternal="true" tag="typeb" limit="50" and
 * Chess < 4.0

=See also=
 * Alpha-Beta
 * Brute-Force
 * Minimax
 * Selectivity
 * Shannon's Type A Strategy

=External Links=
 * [|Subject: brute-force vs. intuition in math & chess] by [|Bill Dubuque], August 1996
 * [|Brute-force search from Wikipedia]

=References= =What links here?= include page="Type B Strategy" component="backlinks" limit="40"
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