Second position

Screen Shot 2015-08-29 at 8.58.42 AM

Another recent position that shows a pretty significant gap in my chess understanding.

Here I thought white has a pretty strong advantage. The knight is good, black is underdeveloped, and white has potential pressure on the queenside down the b- and c-files and perhaps a Bf3. Stray thought during the game was that Kramnik would win this beautifully in a dozen more moves.

Here’s the game continuation, which is just silly maybe not completely ridiculous, but well off target.

15…Bd7 16. Nxd7 Nxd7 17.Qb3 b6 18.Qb5 Qxb5 19.Bxb5 Nf6 20.Ba6 Ba3 21.Rfd1 and I wasn’t able to manage black’s active knight and bishop and retain an advantage, leading to a draw.

Stockfish speaks:

In the diagram, Stockfish says +1.4 or so—a very strong advantage for white. So my overall evaluation was correct. However, I didn’t understand what to do to increase the pressure.

First let’s look at the game line. Qb3-b5 was based on the idea that after …b6, I’d get my bishop to a6 and then get control of the c-file. Interestingly, after 21.Rfb1 instead of 21.Rd1, Stockfish still has white better by half a pawn. That’s a much more manageable deficit for black; I’ve effectively given back an extra pawn. But it wasn’t a completely idiotic line.

Second, let’s go back a bit.

Screen Shot 2015-08-30 at 10.39.16 AM

Here’s Stockfish’s critical line (+1.5) from this diagram:

17. Rfb1 Rac8 18. Qe4 Rc6 19. Rxb7 Rfc8 20. Qd3 Rc1+ 21. Rxc1 Rxc1+ 22. Bf1 Qa4 23. h3 h5 24. Rb1 Rxb1 25. Qxb1

Again with the Rfb1!

In the abstract, I can’t get my head around it. You skip past the potentially hotly contested c-file and bury your other rook on a1, giving black time to play Rac8 with tempo and/or play b6. Queenside problems solved, yes?

[ponders.] The ONLY way I can justify Rab1 in my mind is if I’m going to follow up with a4.

[ponders.] Which I guess would make Rb5 a threat.

So let’s Stockfish these ideas out a little more.

A) 17.Rfb1 b6 18.Qc7 (aha..) Rfd8 19.Bb5 (oh fine, NOW it’s a good move.) Rac8 20.Qb7 eval: +4

B) 17.Rfb1 Rac8 18.Qe4 (what? centralize my queen?) b6 19.Qb7 Qd5 20.Qxa7 eval: +1.6

Dang. The killer attribute of the position is the combination of unguarded stuff not just on b7 but also d7 and e7. The exploitation of the advantage is immediate, not long-term. The rook stays on a1 simply to guard the attacked a2 pawn. All my ratiocination about a4 and Rb5 is just totally irrelevant.

Chess is tactics.


One thought on “Second position

Comments are closed.