2024/03/22 DPA: "Nice Move...But I Have A Better One!"
White to move.
White would like to pin Black's Knight but 1. Rc1 allows either 1. ... Nb5 or ... Nxd5 which protect the Rook.
However, 1. ... Nxd5 doesn't work because now the Knight is pinned by the Bishop so 2. Rxc7+ cannot be met with 2. ... Nxc7 due to the Bishop check.
1. ... Nb5 does protect the Rook and now White's Rook is hanging. I don't see any way around that because there's no way to get the Rook to c2 so it's defended by the King.
But what if White lets the Rook go? 2. axb5 Rxc1 3. Bc2 [to prevent the Rook from retreating along the c file and getting to b1].
But Black can play 3. ... Re1. Can the Bishop escort the pawn and force Black to sac his Rook?
4. b6 Re8 5. Ba4 Rb8 stops the pawn.
1. Rc1 Nb5 2. Bc4 Na7 doesn't work for White since the Bishop can't make a useful move that uncovers the attack on the Rook.
What about 1. Bc4 first? It blocks the Rook's defense of the Knight. But Black has 1. ... Ne4.
Aah, I think I see it: 1. Rc1 Nb5 2. Rc6:
- 2. ... Rxc6 3. dxc6^ [discovered check] Ke7 4. axb5
- 2. ... Na7 means the Rook is unprotected
- 2. ... Rb7 and the Knight falls
That works but let's re-examine whether we can win the Rook or promote the pawn.
I can't see a way for either so I'm going with my idea.
Yup, that was it.
The key was to realize that, while 1. ... Nb5 seems like a great save because it simultaneously breaks the pin and protects the Rook, it's ephemeral: yes, the White Rook is hanging but by playing 2. Rc6, White protects his Rook and maintains the threat on the Knight and the Rook.
This was a subtle move and not so easy to find. It required the solver to override the reflexive desire to capture something [ie 2. Rxc7 or even 2. axb5] and to instead give the "initiative" to the opponent because there are no good moves that save material.
Note: this is not Zugzwang. If Black passed, White would happily play 2. axb5.
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I anticipate today's comment section will be dominated by protests that the puzzle is flawed or that the opponent blundered by playing 2. ... Rxc6 instead of the many superior options or even that Black should have just accepted the loss of the Knight and not played 1. ... Nb5.
Yes, Black had more optimal moves.
Yes, the optimal moves led to a White edge of only 2.x vs the puzzle solution of +M11.
However, don't focus on what Black could have done differently: the point of the puzzle was to highlight the thinking behind 2. Rc6. What was shown in the puzzle was a way to bring closure to the puzzle while still emphasizing the tactic.
If Black had played 1. ... Kf6, for example, and just jettisoned the Knight, the solver would not have had to come up with 2. Rc6.
I don't know about you but finding 2. Rc6 was a lot more difficult for me than 1. Rc1. So in that sense, the puzzle did its job.
Puzzles allow for sub-optimal opponent moves; it gives the puzzle creator lots of leeway. For those who still have an issue with this, think of puzzles as lessons designed to teach a concept, not like a math problem with only one right answer.
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If you're interested in learning how puzzles are constructed and what their aims are [and what's typically allowed vs disallowed], check out the following:
https://www.chess.com/blog/EnPassantFork/no-the-puzzle-is-not-wrong