White to move. How should White proceed?
Chess Daily News from Susan Polgar
Middlegame tactic
White to move. How should White proceed?
1.b4…axb4
2.axb4.and black has to give up his knight or his bishop.
A>2….Nxa4.3.Rxd7 and white is up bishop for pawn
B>2….Re7.3.bxc5 and
C>2….c6…3.bxc5!.cxb4.4.c6!.Rc7..5.Rxd7!
C1>>.5….Qxd7.6.cxd7!.Rxc2. 7.dxe8=Q+.Bf8.8.Nxc2 and white is a piece and rook up!
C2>>.5….Rxd7.6.cxd7.Qxd7 and white is a piece up!
Harry
My instant observation in this situation is that the position of Bd7 looks ugly!
– It is pinned without escape. E.g. Bh3+ Kxh3 would not be an escape.
– To not fall, it is relying on the defense from Nc5. The knight has no move to threat something, so moving it leads to Rxd7.
This certainly invites to play
1. b4?!
but what about black’s reply:
1. … c6! (only option but strong)
Even if white takes this pawn, Ra7 now gives bishop the needed protection and black is free to move knight, e.g. Ne6.
2. bxc5 cxb5
3. cxb6 Rb7
I now tried to improve my first plan by depriving black of the c5 resource:
1. Bc6? Re6!
seems strong for black.
Now I suspect this puzzle may be too difficult for me…
To deprive black of c-pawn with pin of Bd7 remaining could be a point here (at least white is up with a pawn then). One funny line I looked at was:
1. b4 axb4 (can be omitted)
2. cxb4 c6
3. Bxc6 Rc7
4. Bb5 Ne6
5. Qd3 Re7
6. Nd5 forking rooks.
3. … Ne6 (omitting Rc7)
4. Qd3 Re7
5. Rd5 is one possibility with black c pawn gone, strongly attacking e5 pawn.
I’m certainly not able to see all lines here.
I conclude that I don’t find a clear puzzle-like combination giving large advantage, but
1. b4!
will at least deprive black of the c-pawn and give white a strong and lasting edge in this game.
The obvious tactical motif is the pin on the Bishop on the d-file. One of Black’s defensive resources is c7-c6 and the misplaced-looking Rook on a7 defends the Bishop on e7.
I have a bad habit of looking at many unpromising half-ideas: doing something with the Knights for example (even temporarily unpinning with Nd5) or trying to bring the other Rook into the attack by sacrificing the exchange with 1.Rxe7 followed by Red1. But the most promising line I can find is the thematic b3-b4 attempting to remove the guard by attacking the Knight on c5
1. b4 c6 the pawn move not only establishes communication between the Rook and the B on e7 but does so by itself attacking a piece with a pawn Now simply 2. Bxc6 may win a pawn but I think White can go for more
2. bxc5 cxb5
3. c6 …. Winning a piece for a pawn. I don’t see an adequate defense for Black.There don’t seem to be good Knight moves on move 1. Obviously if Black simply retreats the Knight to save it, he gives up protection of the Bishop, but other moves to try to create threats with the Knight simply don’t do enough. For example both 1… Nxa4 and 1…Nxe4 simply lose more material after 2. Rxd7 gaining time with the attack on the Queen, at the very least White wins the Knight as well on the next move.
– Craigaroo
Well, the first thing I notice is the double attack on the pinned bishop at d7. The bishop is double protected by the queen and the knight at c5, so my thought is to try to undermine that defense by attacking the knight at c5 with a pawn:
1. b4
What can black do here? If the knight moves, the bishop at d7 falls. All I can see is that black push the c-pawn to attack the bishop and allow the rook to protect the bishop at d7 as well, but white can defeat this if he plays precisely:
1. …..c6
2. bc5!
Much better than 2.Bc6: [2.Bc6?! Qc8 3.Bd7 Nd7 and white has won only a pawn]. Continuing:
2. …..cb5
3. c6
And the bishop is still pinned and won. White should end up with a piece for a pawn.
pht mentions
1. b4 axb4 (can be omitted as pht says but it allows Black a possible resource that has to be considered and which I overlooked)
2. cxb4 c6 and here I diverge to look at the capture with pawn and subsequent pawn push hitting the pinned Bishop
3. bxc5 cxb5
4. c6 …Rc7 Black tries to counter with his own pin because now the White Q no longer has the added shield of the pawn on c3. I haven’t looked at this (which obviously I should’ve originally) but I’m guessing that White will be ahead even if he gives up his Queen with
5. cxd7 Rxc2
6. dxe8=Q+ Qxe8
7. Nxc2
– Craigaroo
Sorry.
I totally missed that after c6 bxc5! (of course much better than Bxc6) cxb4 there is the pawn push c6 and Bd7 is dead.
So it was quite simple, but I missed it.