< Earlier Kibitzing · PAGE 22 OF 22 ·
|Mar-27-17|| ||maxi: <AylerKupp>, thanks for the explanation on alpha-beta pruning. I find your posts always very interesting.|
|Mar-27-17|| ||maxi: You are right, <Petrosianic>. I remember having similar doubts. But my first two chess books were A Chess Course (or something like that) by Reinfeld and Capa's Chess Fundamentals! Sometimes Capablanca too would put a chess diagram and not quote the source game. I figured people just didn't write down what the original games were!|
Later I realized Capa would do that with positions from his own games.
|Mar-27-17|| ||sudoplatov: A couple of points about alpha-beta. Given a minimax search tree to a fixed depth, alpha-beta will return the same value (not necessarily the same move) as a complete search. The algorithm works by noting that both sides are trying to minimax their play. |
A couple of caveats are in order. The actual speedup depends on move ordering. Always choosing the best move first in a search (the so-called principal variation) helps. In real implementations, the hash table operates more or less independently of the search tree. So the evaluation of a position may not be exactly the same if positions are examined in a different order; mostly this doesn't matter. The alpha beta search is not usually either a depth-first nor a width-first tree search. One does a depth-first to depth 1; then depth-first to depth 2, etc. The early shallow searches help with ordering; filling the hash table, and may find a game-ending move early.
The point of alpha-beta is that nodes that are pruned cannot influence the final score of the root position (assuming that the evaluation function is accurate.) Thus deeper searches always give a better estimate of the actual position.
Another point is that only quiescent positions are considered leaf nodes. In a quiescent position, there are no captures, checks, or pawn promotions.
There are other algorithms (B* is popular) which do forward pruning. So far, in computer chess (as far as I have read) none of these are as effective as alpha-beta; the
|May-01-17|| ||Mithrain: 12 ... e5 shows how well Fischer understood the dynamics of the position (seriously weakening the d5-pawn but gaining a lot of play with his minor pieces).|
|Jul-06-17|| ||The Kings Domain: Poor Byrne brothers, the whipping boys of ol' Bobby. |
Fischer's smooth escalating type of victory is perhaps unmatched in the game. His brilliancies are usually simple but there's a magic to them that can be awe-inspiring.
|Jul-06-17|| ||Petrosianic: <The Kings Domain: Poor Byrne brothers, the whipping boys of ol' Bobby.>|
Actually, Robert was maybe Bobby's toughest US opponent after Reshevsky. You need to study more than just one game.
|Sep-02-17|| ||Penguincw: Video analysis of this game: https://www.youtube.com/watch?v=QHy....|
|Jan-13-18|| ||CheckMateEndsTheGame: On move 14. Why not just play f3?|
|Jan-14-18|| ||GT3RS: Fischer was built in a lab.
A brilliant and underrated short game. Bryne made no obvious error leading up to the fatal queen move or should I say rook move.
From what I've read there was a lengthy analytic artillery exchange via articles in chess publications afterward as Soviet analysts sought to diminish the result by showing Bryne's win with the other move and Fischer responding with analysis to show a plausible draw.
|Jan-15-18|| ||Petrosianic: <GT3RS: Fischer was built in a lab.|
A brilliant and underrated short game.>
Underrated? You've got to be kidding me, Pyle. This is the one that everyone raves about.
|Jan-22-18|| ||scottpi: Why Didn't Byrne play 21. Nf3? What was Fischer's reply to that?|
|Jan-22-18|| ||ChessHigherCat: <scottpi: Why Didn't Byrne play 21. Nf3? What was Fischer's reply to that?>|
Fischer was planning to take the cyanide pill in his signet ring if white played 21. Nf3.
Either that or Bxf3+ 22. Kxf3 Qf6+ followed by Qxc3. That only wins back the piece and leaves Fischer a pawn up, so there's probably better, but I don't see it.
|Jan-22-18|| ||Gregor Samsa Mendel: <scottpi: Why Didn't Byrne play 21. Nf3? What was Fischer's reply to that?>|
21..Qxd2+ 22 Rxd2 Bxc3 and black will be up the exchange and a pawn.
|Jan-23-18|| ||Granny O Doul: And winning more material still with ...Re3 coming up after gathering the exchange.|
|Jan-23-18|| ||Howard: Yes, Fischer could hardly have overlooked 21.Nf3 in his calculations. You just "know" that that move would not have worked for White or even come close---otherwise, Fischer would have acknowledged the move in his book.|
|Jan-30-18|| ||yurikvelo: https://pastebin.com/kqfHg5Qt
|Feb-09-18|| ||Artemio: It's a Gruenfeld similar to his game with the other Byrne (Donald)...|
|Apr-13-18|| ||Justin796: There's a Herbert James Fischer in the 1700s who supposedly won every game with the black pieces, and never won with the White pieces except on Wednesday, 1776!|
|May-26-18|| ||offramp: Has anyone ever seen this game annotated anywhere without the final quip about the grandmasters in the other room?|
|May-26-18|| ||Retireborn: <offramp> I don't think I even know who these two(?) grandmasters were, although I have seen Rossolimo named as one.|
|May-26-18|| ||offramp: <This dazzling move came as the shocker... the culminating combination is of such depth that, even at the very moment at which I resigned, both grandmasters who were commenting on the play for the spectators in a separate room believed I had a won game! -- Robert Byrne>|
The commentators were not Fischer or Robert Byrne. I suppose it was Reshevsky and Kashdan... what other US grandmasters were there?
And how many spectators were there? December 18th, 1963 in New York's deep midwinter - who would come along to see a chess game?
I would imagine a dozen or so spectators and two chess masters, and the masters are being paid five nickels an hour, and the spectators aren't sure how knights move....
|May-26-18|| ||Howard: Soltis mentions who those other two grandmasters/commenters were, and I do recall that one of them was indeed Rossolimo. But I'll be darned if I can recall the other one. Just consult that book, though.|
|May-26-18|| ||Sally Simpson: Soltis only names Rossolimo as does The Chess Review from February. Other sources. The Mammoth Book of Chess and Wade and O'Connell's book only refer to the analysts as other 'Grandmasters.'.|
And how many spectators were there?
Chess Review say 200+ turned up for the Fischer - Reshevsky game and more than that for Round 7 game Fischer v Addison.
|May-26-18|| ||offramp: I can imagine those 200 spectators.
Half of them dressed in Fischer's away kit, and the Reshevskyites dressed as accountants.
Fireworks being sporadically let off. Guys urinating in the guy in front's pocket. Vuvuzelas blasting Fischer's eardrums.
And then, during long pauses in the game, the dreaded Mexican Wave.
|Nov-05-18|| ||PJs Studio: This game was an amazing inspiration to me as a youngster. Fischerís 18...Nxg2!! was the first glimps I had at the depths of calculation needed to win chess games against experts and masters. One of the greatest combos in history. |
The only real question about this game... does 18...Ng2 deserve two exclamation marks, or three?
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