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| Nov-13-08 | | JG27Pyth: What does Alekhine and/or strong engines have to say about 17.Rxc5?! I was lookin at this game with an older engine (fritz 6... don't ask why) ... and the engine thought it was crummy. |
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| Sep-12-09 | | DrGridlock: <JG27Pyth: What does Alekhine and/or strong engines have to say about 17.Rxc5?!> Alekhine writes,
"With correct positional judgment White seeks his salvation in this sacrifice by which he can dispose of one of Black's center pawns. 17 Qa2, for instance, would have been apparently less profitable on account of 17 ... Na6. Rybka does not agree with Alekhine:
Analysis by Rybka 2.2n2 mp 32-bit :
1. = (-0.18): 1.N3d2 Na6 2.Rd1 Nb4 3.Rcc1 Bc5 4.Ne3 Bxe3 5.fxe3 Ng4 6.Nf1 Qd6 7.h3 Nf6 2. = (-0.22): 1.Re1 e4 2.Bxf6 gxf6 3.Ne3 exf3 4.Nxd5 Qe5 5.Nxf6+ Kh8 6.Nxe8 Qxa1 7.Rxa1 Rxe8 3. = (-0.23): 1.Qa2 Na6 2.Qa1 d4 3.N1d2 Nb4 4.Rc4 Bf5 5.Ba3 Rad8 6.Qb1 Bg4 7.h3 Be6 4. = (-0.24): 1.Rd1 Rac8 2.Ne3 Nxb3 3.Qb1 Nc5 4.Bh3 Rc6 5.Qa2 Qc7 6.Rdc1 Ne6 7.Qb3 d4 5. ³ (-0.27): 1.N1d2 e4 2.Ne1 exd3 3.exd3 Nxd3 4.Nxd3 Bxd3 5.Rc3 Bf5 6.Re3 Be6 7.Nf3 Bc5 6. ³ (-0.32): 1.Qb1 Nxb3 2.Rd1 d4 3.Qa2 Nc5 4.N1d2 Na6 5.Qb3 Nb4 6.Rcc1 Bf5 7.Nc4 Rec8 7. ³ (-0.33): 1.Rxc5 Bxc5 2.Nxe5 Bd6 3.d4 Qe6 4.Ne3 Rec8 5.Rxc8+ Rxc8 6.Qf1 Rc7 7.Bh3 Qe7 8. ³ (-0.47): 1.Bxe5 Bxe5 2.Qxe5 Qxe5 3.Nxe5 Nxb3 4.f4 Nxc1 5.Rxc1 Bf5 6.Ne3 Be6 7.Rb1 Rac8 9. µ (-0.78): 1.Rc3 d4 2.Rxc5 Bxc5 3.N1d2 Rad8 4.Bf1 Rd5 5.Nc4 Qd8 6.Rd1 b6 7.Bh3 e4 10. µ (-0.86): 1.Rb1 e4 2.dxe4 Bxe4 3.Rd2 Bxb1 4.Qxb1 Nce4 5.Rc2 Rac8 6.Rxc8 Rxc8 7.Ne3 Nc3 |
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| Sep-13-09 | | Boomie: <DrGridlock>
What is the depth of the search? I assume that for such a long list, the depth wasn't much more than 15. Without the search depth, these are just empty numbers. With the search depth, they are interesting but not particularly meaningful. A proper engine analysis requires hours of scanning variations to verify the evaluations. We really only see this in The World games. Elsewhere I think we are better served by variations with copious comments. The student can't learn chess from numbers. |
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| Sep-13-09 | | DrGridlock: <Boomie> Depth was fairly deep: over 20 moves. I should have reported the depth, but the evaluation I reported took over 4 hours to calculate. Looking at the calculations while Rybka crunched, it was interesing that the deeper Rybka calculated, the less it liked Rxc5. At about 10-15 moves depth there was not much difference between Rxc5, N3d2, Qa2 and Rd1. It was only with the deeper calculation that Rxc5 fared less well. |
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| Sep-13-09 | | nimh: But the difference is only 0.15, which means practically nothing in human vs human chess. Especially back in 1924. I'm not saying they must feel free to do so every time, but if the price for it is that the opponent gets surprised and/or makes him burn the clock a bittle, it is completely justified. |
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| Sep-13-09 | | Boomie: <DrGridlock: Depth was fairly deep: over 20 moves.> Thank you for the prompt reply.
One clue to the value of these numbers is the depth at the last move. Given a depth of 20, with 14 ply lines the depth is 6 at the last move. If you let the engine sit on the last move for a while, you will usually find a different result. This is the main reason that infinite analysis has little value in The World games. Even RV's monster searches at depths of 30 or more are used only as baselines for more thorough analysis. I understand the temptation to post these numbers. If you look earlier in this page, you'll see me dumping a great load of unannotated numbers. However I also posted some commented lines. For example, here's one of my posts from 7/22/08: <20...Bd6 (0.26/21) looks bad or at least pointless. Better is 20...Qd6 21. Kh2 (21. d4 Bb4 22. Rxc8 Rxc8 23. Qd1 Ne4 (-1.20/20)) Bxe3 22. Rxc8 Rxc8 23. fxe3 (-0.81/20)> Notice that the eval and depth are given after the move where the analysis took place. Still I think I should have explained why Bd6 was pointless and not just given the numbers as "proof". On a game page, a student is better served by explanations. Why is one move better than another? Alekhine's comment is worth more than a page of numbers even if the engine disagrees. Did Dr. Lasker have anything to say about it? This kind of commentary with a brief reference to an engine evaluation is more useful. |
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| Sep-13-09 | | Boomie: <DrGridlock>
Here is an example of analysis that nicely blends commentary with the engine. Keypusher uses Tarrasch's comments with some later analysis. This game is very instructive for the student.
Lasker vs Tarrasch, 1908 |
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| Sep-13-09 | | DrGridlock: <Boomie> I agree that there are times that just posting lines and evaluations does not give a complete picture of what is happening in a game. Here is an example of where I added commentary to Rybka evaluations: Keres vs Petrosian, 1959 Note that <JG27Pyth> asked,
"what does Alekhine say," and "what does a search engine show?" I thought it was succinct to answer those two questions. I don't think that I have "refuted" Alekhine's analysis, but I do think that the several moves that rate approximately evenly from Rybka indicate the move is not the turning point (or necessity) in the game that Alekhine seems to think it was, and that there is room for further analysis and lines to explore the game move and alternatives. |
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| Sep-13-09 | | Boomie: <DrGridlock: Note that <JG27Pyth> asked, "what does Alekhine say," and "what does a search engine show?"> That's true. My comments were a bit out of context. |
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| Sep-14-09 | | AnalyzeThis: Only Richard Reti would play Queen to a1, followed later by Queen to h1, against a former world champion. You have to smile at this. |
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| Sep-14-09 | | Boomie: <AnalyzeThis: Only Richard Reti would play Queen to a1, followed later by Queen to h1, against a former world champion.
You have to smile at this.>
The guy was so hyper he should have been on Ritalin. |
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Sep-15-09
 | | Pawn and Two: <Boomie & DrGridlock> Regarding your discussion of White's choices at move 17, here are Fritz's top four choice: Fritz's first choice: (-.49) (22 ply) 17.N3d2 Na6 18.Re1 Nb4 19.Rcc1, (-.48) (25 ply) 19...Ng4 20.h3 Nf6 21.Ne3. Additional analysis would be needed at this point, but Black has a number of reasonable continuations: 21...Qe6, or 21...Qd7, or 21...Red8. At 19 ply Fritz indicates 21...Qe6 is Black's best choice, with a slightly increasing advantage (.53). Fritz's 2nd choice: (-.58) (22 ply) 17.Qa2 d4 18.N1d2 Na6, (-.58) (23 ply) 19.Qb1 Nb4 Rc4 Nfd5, or (-.57) (23 ply) 19.Qa1 Nb4 20.Rc4 Bf5. Fritz's 3rd choice: (-.59) (22 ply) 17.Rd1 Nxb3 18.Qa2 Nc5 19.Ne3 Na6 20.Rcc1 Nb4 21.Qb3 d4 22.Nc4, (-.76) (20 ply) 22...Bf5 23.e3 dxe3 24.Nxe3 Be6. If White next plays 25.Nc4, Black has a very strong reply with 25...Rad8!. This line, (17.Rd1), is clearly inferior to the (17.N3d2) line. Fritz's 4th choice is the game continuation 17.Rxc5. Alekhine, in the tournament book, indicated this sacrifice was White's best chance, as he can dispose of one of Black's center pawns. While computer analysis indicates 17.Ncd2 was a better move, 17.Rxc5 may have contributed to some of the inexact play that followed, where White could have gained the advantage. Fritz indicates the following continuation: (-.60) (22 ply) 17.Rxc5 Bxc5 18.Nxe5, (-.68) (23 ply) 18...Qd6 19.Ne3 Bxe3 20.fxe3 Rac8 21.Re1. At this point, Fritz indicates: (-.71) (20 ply) 21...Rc2 22.Bd4 Qb4, is a good continuation for Black. Instead of 18...Qd6, also favorable for Black was: (-.66) (23 ply) 18...Bd6 19.f4 Bc5+ 20.Bd4 Rac8. After 17.Rxd5 Bxc5 18.Nxe5, Lasker missed the correct continuation, and played 18...Rac8. Then Reti missed his best continuation: (-.46) (20 ply) 19.Bh3! Rc7 20.d4, where White may survive. After 19.Ne3? Qe6, Fritz preferred: (-90) (20 ply) 20.Bf3 Bf5 21.Nxf5 Qxf5 22.d4. Reti played 20.h3, and Lasker then had a strong continuation available: (-.91) (21 ply) 20...h5! 21.Kh2 Bf5 23.d4 Bd6, or by 20...b6!, the move Alekhine recommended, (-.88) (21 ply) 20...b6! 21.Kh2 Bf5. At this critical point, Lasker erred with 20...Bd6? 21.Rxc8 Rxc8, allowing Reti the chance to gain the edge with 22.N5g4!. |
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Sep-15-09
| | Pawn and Two: In my last posting, in the 2nd paragraph, regarding Fritz's first choice 17.N3d2, the last sentence should read, "At 19 ply Fritz indicates 21...Qe6 is Black's best choice, with a slightly increasing advantage (-.53)". |
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| Sep-15-09 | | Boomie: Perhaps Lasker knew that Rxc5 was technically inferior to N3d2. But OTB chess is about practical chances. When your position is drifting, stirring the pot can present your opponent with more difficult choices than he can handle. Here is a quote from Kasparov in OMGP I. This is about game 4 in Lasker's match with Tarrasch. Tarrasch vs Lasker, 1908 "Lasker realised perfectly well that his only chance of avoiding a prolonged and gruelling defence was to dislodge Tarrasch from his confident state. To do this he had to create something unusual, contrary to all the positional rules and standards of chess wisdom!" By shaking the tree, Lasker's opponents have to devote extra resources and time into solving the new problems. Frequently they fell into time trouble or lost their way. One mark of a true champion is the ability to rescue an inferior position. Lasker used psychology to save many of these games. After all, chess is a game played by humans. And humans have frailties which can be exploited. The game is less interesting without them. |
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| Sep-15-09 | | Boomie: Lasker won this tournament finishing 1.5 points ahead of Capablanca and 4 (!) points ahead of Alekhine. At age 55, this result made him the highest rated player in the world according to Chessmetrics. And the highest rated 55 year old ever at 2833. Any best players of all time list that does not include Lasker is suspect. |
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Sep-15-09
| | Pawn and Two: <Boomie> Do you mean Reti, instead of Lasker, in your posting: <Perhaps Lasker knew that Rxc5 was technically inferior to N3d2. But OTB is about practical chances.> Our computers may prefer 17.N3d2 over 17.Rxc5, however, I agree that Reti's 17.Rxc5 provided some additional practical chances, and complexity to the issue. In any case, Lasker missed his way at move 20, (20...h5! or 20...b6!), and played the much weaker 20...Bd6? Unfortunately for Reti, in this case the knife cut both ways, as after 20...Bd6? 21.Rxc8 Rxc8, he then missed 22.N5g4! |
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| Sep-15-09 | | Boomie: <Pawn and Two: <Boomie> Do you mean Reti, instead of Lasker> Oops. The move is so Laskerlike that what's left of my mind switched them. Thanks for the head up. Reti is trying to do a Lasker with that move. Unfortunately for him that doesn't work so well against WCs at the top of their game. |
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| Feb-12-10 | | Dravus: Reti pulls his Queen to a1 (at 14) to gun up his fianchettoed Q Bishop, then flings her to h1 (at 25) to load up the flanked K Bishop. Finally, Reti plays Qh1-b7 (31) which curiously, spanning only six squares (by diagonally hypo-tenuda-ting them), was the longest queen move of the game (by radical 72 minus 7 squares). A tribute to Judy Tenuda in a loss by Reti. |
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| Aug-19-11 | | K9Empress: "My best game from New York 1924" --Lasker |
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| Mar-21-12 | | LoveThatJoker: Guess-the-Move Final Score:
Reti vs Lasker, 1924.
YOU ARE PLAYING THE ROLE OF LASKER.
Your score: 100 (par = 67)
LTJ |
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Dec-03-15
 | | Domdaniel: After this, White won a large majority of the games in this variation (Reti Opening, Double Fianchetto vs London System). Euwe's 1934 win against van den Bosch is a good example. |
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| Apr-02-22 | | Mathematicar: Can someone explain to me Lasker's 24th move (24... h5)? |
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Apr-03-22
 | | moronovich: <Mathematicar: Can someone explain to me Lasker's 24th move (24... h5)?> Good question.
It is mainly to weakening g3.As after hxg3 the white king is more vulnerable.Especially with a BB taking part from d6.Also the e-file is opened for further black pressure. A classic manouver it is. |
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| Apr-03-22 | | Olavi: h5-h4xg3 weakens the whole white structure. Black needs to make something happen, even if he is an exchange up, just look at the dead Bh7. It would be easy to let this slip, suddenly white would have total control. |
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| Apr-03-22 | | Mathematicar: Thanks, on the Black's side the move doesn't make much sense to me and it seems risky, but when I turn the board and look at the game from a White's perspective the move really looks powerful. |
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