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| Jul-21-09 | | PinnedPiece: Missed this. Pretty tough for a Tues. |
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| Jul-21-09 | | karnak64: Yeah, I suckered for Nxc6 as well. Thought it was pretty. Wasn't pretty enough. And that goes for my dating life when I was younger, too ... |
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Jul-21-09
 | | TheDestruktor: <Once: Today's puzzle is a rare example of a double-defensive move. Normally, we see moves that double-attack - a fork, a skewer, a pin. Indeed, the tempting 17. Nxc6 is itself a double attack - it threatens both 18. Rd8# and 18. Qxb5. What most of us missed is that black has a double move of his own which both defends d8 and the Qb5. 17...Ba6 simultaneously uncovers the Ra8's defence of d8 and protects the Qb5.> Perfect explanation. |
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| Jul-21-09 | | Patriot: <TheDestruktor: <Once: Today's puzzle is a rare example of a double-defensive move. Normally, we see moves that double-attack - a fork, a skewer, a pin. Indeed, the tempting 17. Nxc6 is itself a double attack - it threatens both 18. Rd8# and 18. Qxb5.
What most of us missed is that black has a double move of his own which both defends d8 and the Qb5. 17...Ba6 simultaneously uncovers the Ra8's defence of d8 and protects the Qb5.> Perfect explanation.>
Very true. And apparently it's such a rare defense that it didn't register with most of our tactical arsenal. My only saving grace in finding the right move, is that I chose a simple win over what appeared to me as a potentially more complex win. Usually when it comes down to a simple win that is completely forcing vs. a win that involves a quiet move, I will choose the simple win knowing that I'm not overlooking something. To me that is just practical chess, which puzzles usually don't acknowledge. |
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| Jul-21-09 | | DavidD: Today's game is an excellent example of chess thinking and how it can go wrong. Three important lessons can be learned from the excellent comments made by players. Exactly why did so many choose 17.Nxc6 instead of 17.Rd8+? 1) While 17.Nxc6 is forcing, it just isn't forcing enough--Black has a defense: 17...Ba6. Instead, always examine the most forcing moves in a position: checks and captures. 17.Rd8+ is a check and more forcing than the Knight capture. 2) In calculation, transpose move orders as a way of checking analysis. Clearly 17.Nxc6 is played with two threats: Rd8 mate and Qxb5. Clearly players "saw" Rd8 but changing the move order and playing Rd8+ immediately wins. 3) Overlooking the opponent's reply. Comments indicate that players were satisfied with 17.Nxc6 but did not find the one reply to both threats: 17...Ba6 covering the d8 square with the Rook and protecting the Queen. Take time and really examine the position! One reason we don't get better is that we don't change our thinking processes. Lessons from the game should be remembered. Examine ALL checks and captures in a position first! In calculating, transpose move orders! Examine ALL reasonable opponent replies! |
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| Jul-21-09 | | awfulhangover: Oh no! I thought for 5 seconds, "played" Nxc6 and felt so smart, and now I feel like a jerk. Ba6 refutes it. |
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| Jul-21-09 | | Julian713: Excellent puzzle! I saw the a6 trap, avoiding Nxc6, but for some reason didn't connect to the rook sacrifice check. In a real OTB game I would probably have played Qxc4, because it forces Bxe6 to prevent mate (any other block loses material)...followed by 18.Qxb5...cxb5, 19.Bxb5+ and white has regained its material disadvantage as well as threatening down the d-file. |
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| Jul-21-09 | | agb2002: <johnlspouge: < <al wazir> wrote: <dzechiel: . . . I am so ashamed.>
Don't be. By regularly posting a record of your thoughts, right or wrong, you have set an example for a whole school of solvers. > As part of that "school", I would like to add that it takes real courage to post ex tempore analysis, when the only benefit to the author is to immortalize his own fallibility.> You are overlooking the unquestionable benefits of self-flagellation ;-) -----------
This puzzle reminds me of Mieses vs Breyer, 1914. Let's try some figures (use your own!) this time with the same notation. Assume, for example, P(B) = 0.6, P(C) = 1 - P(B) = 0.4, P(A/B) = 0.1 and P(A/C) = 0.05. Then, the probability of being too confident, that is, under the influence of CG's rating knowing that one made a mistake is P(B/A) = P(A/B)*P(B) / [P(A/B)*P(B) + P(A/C)*P(C)] =
= 0.1*0.6/(0.1*0.6 + 0.05*0.4) = 0.75
Conclusion: ignore CG's rating and just go for it. Yesterday's, for example, was not so 'very easy'. |
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| Jul-21-09 | | Patriot: <DavidD>
Excellent comments! Especially where you stated "One reason we don't get better is that we don't change our thinking processes." Sometimes it takes a stronger player to point out where our thinking went wrong. One good example is where a player fails to consider a key candidate move because they fail to consider ALL of their opponent's pending threats first. I hear players all the time talk about books they read on annotated games or books that go into detail about a specific opening. But the REAL reason they are not improving is that while they are adding positives (gaining more knowledge about openings for example), they are not subtracting negatives (removing the flaws in their thinking, practicing tactics they commonly miss, etc.). In that case it doesn't matter how many hundreds of books they read, they're never going to get much better until they can eliminate the mistakes they keep making. |
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| Jul-21-09 | | Pawnage: Maybe my not being very clever made finding Rd8 easy :) Nxc6 was never an option for me. |
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| Jul-21-09 | | johnlspouge: < <agb2002> wrote: <<<>>johnlspouge: [snip] As part of that "school", I would like to add that it takes real courage to post ex tempore analysis, when the only benefit to the author is to immortalize his own fallibility.> You are overlooking the unquestionable benefits of self-flagellation ;-) > You are correct, of course. I just love being wrong - ask my wife ;>) |
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| Jul-21-09 | | gerpm: Took a few minutes but I found it. |
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| Jul-21-09 | | kevin86: I first saw 17 ♘xc6,Δ mate and the queen-but ♗a6 or ♕b6 stops both threats. Then I saw that the reverse mode-not threaten ♖d8,but MOVE ♖d8. The result is that the queen is won after ♔xd8 18 ♘c6+ Black tripled her pawns at move eleven!! |
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| Jul-21-09 | | YouRang: For a moment there, I thought 17.Nxc6 was the solution (removing the queen's defender while threatening Rd8#), but then 17...Ba6 solves both problems. So, I tried the more forcing 17.Rd8+ first, which is a fine example of a decoy move, because 17...Kxd8 leads to 18.Nxc6+, an interesting "check while removing defender move". |
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Jul-21-09
 | | OhioChessFan: Saw this one instantly. I needed that after some of the Tuesday and Wednesday beatdowns I've suffered. |
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| Jul-21-09 | | agb2002: <Patriot: ...
I hear players all the time talk about books they read on annotated games or books that go into detail about a specific opening. But the REAL reason they are not improving is that while they are adding positives (gaining more knowledge about openings for example), they are not subtracting negatives (removing the flaws in their thinking, practicing tactics they commonly miss, etc.). In that case it doesn't matter how many hundreds of books they read, they're never going to get much better until they can eliminate the mistakes they keep making.
>
I strongly agree.
Another problem is our attitude. We cannot go to a battle armed with just a party blower and not wanting to use it (there is a chance that our enemy dies of suffocation while they laugh at us) and probably this is what sometimes happens to us when we are told that the puzzle is easy. |
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| Jul-21-09 | | johnlspouge: < <kevin86> wrote: [snip] tripled <her> pawns at move eleven!! > Your inference is reasonable, but Etienne Bacrot, unlike his name, does not have a feminine form. By the way, as Cyrus the Virus said to Garland Green in "Con Air" (with John Malkovich's wonderfully subdued nasal tones): Love your work. Somehow, you are on my favorites list. It must be the avatar :) |
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| Jul-21-09 | | Antonius Blok: Seems that we've all had been trapped like "Tooo confident little rats"!
Therapist: Now, I want to present you Antonius
Antonius: Hi everybody
Therapist: Say Hi to Antonius
Anonymous Kibitzers: Hi Antonius
Therapist: So, Antonius, can U Tell Us why are you here today? Antonius: ... Therapîst: Antonius? Did you herad me?
Antonius:...
Therapist: You don't have to be SHY Antonius, C'mon.
Antonius: I mean... but...
Anonymous Kibitzers (They are all from Chessg***.com snirk snirk): ... Therapist:I know it's really difficult for you to talk about IT, but you don't have to fear, we are all here your friends, we won't judge you Antonius... Antonius: Ok, (I don't mind)My name is Antonius Blake and... and... I didn't got the move... It was a... It was a ttthursd#~)+@... , ... (God what a shame)I played Nxc6! Anonymous Kibitzers:... (what a shame)
Therapist:(poor little damned)It's good, it's really good Antonius, you made a great step, the first step is to admit it, and you did it! Applause Antonius Everybody Anonymous Kibitzers(I can say names):hum ...Yeah, yeah Nxc6... Maybe next time... Try harder... I like knights, I like knights... You're not Capblanca after all, you're just human... Abandon Chess...why didn't you try h3?...No?... Patzer, patzer, patzer, snirk snirk snirk THE END |
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| Jul-21-09 | | jfshade: Unlike many days, today I had the patience to look carefully at 17.Nxc6 and found that Ba6 solved both of black's pressing problems. After that, rook sac for Q popped right out at me. But in a game situation, I would probably jump on Nxc6 due to its initially convincing forcing appearance. |
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| Jul-21-09 | | CHESSTTCAMPS: <Antonius> Thanks Therapist - is there a fee? Because many of us fell into the 17.Nxc6?? trap, it seems reasonable to determine whether it would cost a full point or a half-point. The quest for chess truth may deepen the misery, but here goes: After 17... Ba6 18.Qxb5 Bxb5, black's "meaningless" c-pawn and white's undeveloped Rh1 (and now vulnerable king) cause major headaches for white. 
click for larger viewFrom this position, I used engine analysis to speed the process of determining whether 19.Nd4 or 19.Be5 was the best continuation. In fact, 19.Nd4 Ba4! forces white to give up the exchange; after 20.Rc1 Ba3 the c-pawn can't be taken. That leaves 19.Be5 Bxc6 (best) 20.Bxf6 c2! and now:
A. 21.Bxh8 Bb4+ 22.Kf1 cxd1+ 23.Bxd1 c3 (not O-O-O 24.Bxg4+) 24.Bxg4 c2 25.Bb2 Rd8 26.g3 (Ke2 Bb5+ 27.Ke3 [Kf3 Rd1 wins] Bd2+ 28.Kf3 Rd3+ 29.Ke2 Bc3 is winning) Rd1+ 28.Kg2 Bxe4+ 29.c3 Bd3 and white can't stop an eventual Bd2, forcing white to give up a piece for the c-pawn. B. 21.Rc1 Bb4+ 22.Kf1 Rb8! (Chessmaster's move, not mine) 23.Bxh8 Ba3 24.Bxc4 (Rxc2 Rb1+ 25.Bd1 Rxd1+ 26.Ke7 Rxh1 leaves white a piece down without compensation) Bxc1 25.Bb3 Bb5+ 26.Kg1 (Ke1 Rd8 27.Bxc2 Bd2+ 28.Kd1 Bc3+) Rc8 27.h3 Bf4 wins B.1 23.Bxc4 O-O 24.Rxc2 Bxe4 25.Re2 Rfe8 26.f4 Bc5 27.Rxb2 (Bxb2 Rb4) Rxb2 28.Bxb2 Rd8 29.Bc3 Rd1+ 30.Be1 Ra1 with a winning bind. Fritz or Rybka may find more, but my conclusion is that the blunder costs the full point. |
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Jul-21-09
 | | fm avari viraf: At first sight, I spotted the most enticing 17.Nxc6 but soon dicarded as Black could defend himself with 17...Ba6. Then soon I saw the crushing 17.Rd8+ sending the Black King in the coffins. |
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| Jul-21-09 | | ruzon: I think the allure of 17.♘xc6 is that it appears to win ♕ for ♘♙, while 17.♖d8+ "only" wins ♕ for ♖♘♙. At least that's how my sloppy thinking went. |
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| Jul-21-09 | | MostlyAverageJoe: <ruzon> it wins quite a bit more... look deeper. |
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| Jul-21-09 | | akapovsky: You must always check your analysis twice and carefully evaluate the position before making a move.Nxc6 is easily defended with Ba6 with that in mind I went to my next candidate move Rd8+.The golden rule is <take your time> it dosen't help to solve a puzzle in 3 seconds if you don't really know what's going on. |
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| Jul-21-09 | | whiteshark: Got it in a second run. |
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Later Kibitzing> |
Kibitzing
sac: 17.Rd8+
