Resetting the Objective - Pt. 2: Evaluating Endpositions
black to move

Resetting the Objective - Pt. 2: Evaluating Endpositions

PhasmicChess
NM PhasmicChess
Apr 4, 2018, 3:13 PM |
1

In spite of it's great complexity, the calculation process can be broken down into a four-part cycle, as follows: Objective => Suggestion => Calculation => Evaluation. In this context, we can define an objective as a desirable outcome and/or a fixed point from which to calculate. At various points, any part can feed into any other part, though the suggested flow is more or less normal.

For example, in the above position, from a Daily Chess game of mine, white had just played Be3. The bishop on d3 is unprotected, which gave me the idea of using it in my calculations. Objective: make use of the d8-rook's x-ray along the d-file to win a pawn. Suggestion: Bxe5 was my first thought, but c5 is obviously a consideration too. Calculation: 1...Bxe5 leads to the forced variation 2.dxe5 Rxd3 3.Qe2, and black is losing the exchange, because the rook and knight are both en prise.

That led me to calculate my second idea: 1...c5 2.dxc5 (2.Qe4 is also a reasonable move, albeit one I didn't even notice during my calculations) Rxd3 3.cxb6 Bxb6 and now, Qe2 runs into the tactic Rxe3!, with the follow-up Ng3. However, white doesn't have to play Qe2, and I felt that this was only so-so for me. Indeed, 4.Rfd1 is quite alright for white. It turns out, black can't win the pawn. I'd noticed the idea of sacrificing an exchange on e3, so I returned to my original line of calculation with a new objective: to sac an exchange on e3.

 

 
 
Okay, that was a somewhat lengthy example of a series of forced calculation and evaluation. Often, this evaluation of endpositions is mishandled at a critical juncture in the game. Like in the following position, from a Pro Chess League game between two Grandmasters.



I hope all of this is helpful to anyone reading it. For me, it's a way to evaluate what I've learned about the calculation process, and perhaps share some of it with others. I will continue this series, looking into (sometimes) complex calculation, with a focus on setting and resetting an objective, with a third part in the near future.