Jim said:
"I am interested in how pieces are lured off the back rank to capture . Then forced to block a rook check. on the 8th rank .the attack now has a tempo to play with."
Black to move
r3r1k1/5ppp/2pR1q2/2P5/1p2B3/1Q4Pb/1P3P1P/4R1K1 b - - 1 1
[solution]
In the comments of the previous post I was somewhat worried about whether my dataset of just 111 problems was rich enough to guarantee a sufficient frequency of occurrence of the tactical elements. With that in mind I had another look at the dataset I work with. I soon realized that there is no reason to worry for two reasons.
The first reason is that I hang everything onto the PoPLoAFun framework. That framework appears in every game, so I have to work on the details anyway. As long as that condition is met, I'm making progress.
The second reason is that I fiddle around with the pieces a lot. Always with the question in mind "what if ... ?". Thus milking all details out of the position.
Have a look at the following diagram.
White to move
2rr1bk1/p1nq1p1p/1p1N2p1/3QP3/8/6B1/PP3PPP/2R2RK1 w - - 1 1
[solution]
After I solved this position I started to fiddle around with the pieces, and I asked myself "what is the difference between 1.Qb7 and 1.Qc4". Can you find the difference?
This will take some time for thought....
ReplyDeleteTo me, the distinction is hidden. 1. Qc4 does one thing: White is adding an (indirect) attacker to the c8-square, which was B.A.D. prior to this move. On the other hand, 1. Qb7 adds a direct attacker to the c8-square BUT (crucially) it also makes the d7-square B.A.D. [1:1]. Given the choice between doing ONE good thing or doing TWO good things. In general, ceteris paribus, give preference to doing TWO things to ONE thing with a single move.
ReplyDeleteA quick check shows that Black cannot effectively directly counter-attack the White Queen with 1… Rb8: White simply captures on c7 with 2. Qxc7.
After 1. Qc4, Black can capture the “octopus” with 1… Bxd6. After 2. exd6 Ne6, the d8-square is still B.A.D. but White cannot capture on it because the first capture loses the Queen for a Rook. The White pieces are in the “wrong” order on the c-file for a safe capture.
Close, but no cigar. 1.Qb7 pins the black knight against the black Queen. Which makes the black rook on d8 overloaded. Which makes Rc8 under defended.
ReplyDeleteIt is a chain of simple salient cues, waiting to be seen. Pin, overload, under defended target.
When you see all salient cues easy, they arise when following the chain of logic.
But when you don't see the salient cues easy, you need to calculate and work with candidate moves and a tree of analysis. Which is time and energy consuming and error prone.
Hence I think that fiddling around with the pieces proves that even a limited amount of problems provide way more frequency of occurrence of tactical elements than you are inclined to think.
Those chains of salient cues are the things we need to absorb. Can you discover that chain in the first diagram?
ReplyDeleteWell . The first diagram is easy peasy the second not so much. I will set up on my chessboard and follow along from here. Interested in how the logic flows from here.
ReplyDeleteYou are right: SEEing the salient cues enables us to SEE the necessary logic. It feels almost like linear thinking along a single branch.
ReplyDeleteI focused only on the obvious difference between the two moves 1. Qb7 and 1. Qc4. I SAW the ramifications of creating TWO B.A.D. squares (c8 and d7), with the resulting overload of BRd8 as well as the potential capture on the c7-square after clearing the LoA of the WBg3 by capturing with the White Knight on c8. White gains the necessary tempo and superiority to capture on the c7-square by pushing the e5-pawn, attacking the Black Queen, concurrently gaining superiority on the c7-square [3:2].
Moving right along. . . responding to Jim’s question:
Here are some more examples:
- Source: The Art of Chess Combination, A Guide for all Players of the Game, No. 84, pg 88, Eugene Znosko-Borovsky, © 1959.
Adams – C. Torre, New Orleans, 1920
FEN: 2r1r1k1/pp1q1ppp/3p1b2/3P4/3Q4/5N2/PP2RPPP/4R1K1 w - - 0 1
- Source: Fundamental CheckmatesChapter 4, Mating Positions Using A Single Piece, 2: Rook Mates, Antonio Gude, © 2016.
Bastrikov – Goglidze, USSR Team Ch, Riga, 1954
FEN: 5rk1/7p/3p1rp1/3Pp3/3qP3/6Pb/3RQ1NP/4R2K b - - 0 1
Zair – Am. Rodriguez, Ubeda, 1998
FEN: 3q2k1/5rpp/3b2N1/7R/3B2Q1/r7/6PP/6K1 b - - 0 1
the first one is not easy for me either as I see that the Queen intially supports the rook blocking a back rank mate.
ReplyDeleteThe first one is not easy for anybody. It is a very famous example. It is about e8. The other pieces of black are totally restricted to the defense of e8. This limits their possibilities. While white can try anything to lure the black defenders away from e8.
Delete"It feels almost like linear thinking along a single branch"
ReplyDeleteThat is the point I want to make. By following the chain, you prune the branch defacto. You reverse the order of branching and pruning. There is only one branch, which you follow. Only when a branch gives no good result, you prune it and look for another branch. This way, there is always only one branch to look at. Hence you need no branch administration.
The PoPLoAFun system is in fact only one branch. The line from attacker to target.
A quick “look” at the first position shows that the White King is confined to the back rank. I SEE that if Black can get a major piece unscathed to that back rank, White could be checkmated. That’s NOT going to happen immediately unless White “cooperates” in his own demise. I don’t know the time situation, but Korchnoi may have thought that he had everything covered. GM Stockfish thinks White had a “plus/equals advantage prior to his 25th move.
ReplyDeleteThe first LoA is e8 ↔ e1. The second LoA is a8 ↔ a1.The WBe4 is on a B.A.D. [1:1] square. As soon as White played 23. Rd6, it would be natural for Black to LOOK at clearing the back rank for a fatal (?) check by the BRa8. That is the first salient clue. So shuffle the pieces in the mind’s eye: 23. Rd6 Rxe4 24. Rxe4 (forced). Remove the WBe4 and BRe8, and visualize the WRe4. White has control of d1 (WRd6 and WQb3). Now comes the shocker: 23...Qxd6. WHY? Because it removes one of the two defenders of d1, and SURPRISE!, White now only has one “defender” for e1 and one “defender” for d1 in response to BRa1 CHECK. White cannot take that cheeky BQd6! Sadly for White, he has to resign himself to the loss of a piece to avoid a back rank mate. Black’s 25… Qxc5 is pure sadism.
“When your opponent is drowning, throw the son of a bitch an anvil.” — James Carville
The first position is from the following game, after White’s 23rd move.
Korchnoi, Viktor (2680) vs Levenfish, Grigory (2677)
Date: 1953
Event: Ch "Trade Unions" (team), Ch URS (team), Leningrad (Russia)
Round: 1
Result: 0-1
Opening: Catalan Opening, Closed Variation (E07)
Problems: 80388
1. c4 Nf6 2. Nf3 e6 3. g3 d5 4. Bg2 Be7 5. O-O O-O 6. d4 Nbd7 7. Qb3 c6 8. Nc3 b6 9. cxd5 exd5 10. Bf4 Bb7 11. Rad1 Re8 12. Rfe1 a5 13. a3 Bf8 14. Ne5 Nxe5 15. Bxe5 b5 16. Bxf6 Qxf6 17. e4 b4 18. axb4 axb4 19. Na4 dxe4 20. Nc5 Bxc5 21. dxc5 Bc8 22. Bxe4 Bh3 23. Rd6 Rxe4 24. Rxe4 Qxd6 25. Qxb4 Qxc5 26. Qe1 g6 White resigned.
Ah I see on the first one.
ReplyDeleteWhites D-file Rook move to D1 supported by Whites queen holds whites game together . Removal of Rook (Possible) and Deflection of the Queen from guarding d1 (doesn’t work) are two options.. So White has a choice of his next tempo after QXR take the queen and be checkmated or Re1 to prevent checkmate and try to fight on a rook down. A removal of the guard motif. (?)
Yes, removal of the guard is true
DeleteI could "SEE" 24... Qxd6 as a "removal of the guard."
Deletehttps://www.chessgames.com/perl/chessgame?gid=1080928 thanks for additional context
ReplyDelete