Kotok-McCarthy-Program

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John McCarthy operating Kotok-McCarthy [1] [2]


The Kotok-McCarthy-Program,

also known as "A Chess Playing Program for the IBM 7090 Computer" was the first computer program to play chess convincingly. Between 1959 and 1962, while student of John McCarthy at the Massachusetts Institute of Technology, Alan Kotok and his fellows Elwyn Berlekamp, Michael A. Lieberman, Charles Niessen and Robert A. Wagner wrote a chess program for the IBM 7090. Based on Alex Bernstein's 1957 program and routines by McCarthy and Paul W. Abrahams, they added alpha-beta pruning to minmax, at McCarthy's suggestion. The Kotok-McCarthy-Program was written in Fortran and FAP, the IBM 7090 macro assembler.

Type B

Kotok-McCarthy was a selective Shannon Type B kind of program. It considered only a few plausible moves as function of increasing ply

{4, 3, 2, 2, 1, 1, 1, 1, 0, 0}

and therefor had some tactical flaws. Quote by Richard Greenblatt concerning Mac Hack VI from his Oral History [3]:

Most of this printout was analysis from the Kotok program. And I also saw some kind of a textual thing, which I don’t believe was Kotok’s thesis, but which had some of the same information as Kotok’s thesis. It was probably some kind of a technical report, or something, that was anticipatory to Kotok’s thesis [4]. Anyway, one of the things I remembered, and which I just talked with Kotok, as a matter of fact, a few days ago, was the detail that they had is Alpha Beta, and so forth, and they had these whips, and the whips were set at 4, 4, 3, 3, 2, 2, 1, 1. In other words, that was how many. It would first look at the top ply. It would look at the four best moves. The next plys, it would look at the three best. Next ply, two best, next ply, one best. Well, I just recognized immediately that that was incredibly wrong.

You see, basically looking at only one wide, you just have no signals or noise function. In other words, you look at one move, which you think is the best, but there’s a tremendous amount of noise. Well, you look at some more moves, and if you find that one of those are better, you’ve effectively rejected some noise. Well, essentially the thing that I knew that they did, they were very weak chess players, both McCarthy and Kotok. And basically they had a very romanticized view of chess. And so I knew, however, that chess is a very, very precise game. And you really- the name of the game is take the other guy’s pieces, and you don’t just go along. In any kind of a strong game, you don’t just lose pieces, win pieces, lose pieces, win pieces. I mean, if you lose even a single pawn without compensation, then you may have drawing chances, if you’re lucky. Otherwise, the game is lost. Losing more than one pawn almost invariably results in loss of the game, period.

Stanford-ITEP Match

see main article Stanford-ITEP Match

After graduated from MIT, Kotok lost interest in computer chess but his program remained alive. When McCarthy left MIT to take charge of the Artificial Intelligence Laboratory at Stanford, he took Kotok's program with him and improved it's searching. At the end of 1966 a four game match began between the Kotok-McCarthy program, running on a IBM 7090 computer, and a program developed at the Institute of Theoretical and Experimental Physics (ITEP) in Moscow which used a Soviet M-2 computer [5]. The match played over nine months was won 3-1 by the The ITEP program, despite playing on slower hardware.

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