kbhearn wrote:Well you asked why the engine wouldn't go kingside, and looking at engine lines quite simply why they'd avoid it as a sample line would be something along the lines of :
15 ... o-o 16. o-o Be6 17. Nd2 Qd7 18. Rae1 where black will never be able to play f5, white has more space, more activity, and all the chances. f4+g4 seems to be quite playable in most lines simply because black has no activity, opening lines on the kingside means his king is opened up too and white is better placed to take advantage of it. Is it more likely to survive than with the king on the queenside? maybe... But it is an entirely different game to analyse and may not be sufficient.
Regarding your line: 16 ... Qd7?! 17. Nh4 g5? leads to difficulties after 18. Nxf5 Qxf5 19. f4 gxf4 20. Rae1 at which point in multipv several attempts to flail around are presented with evals ranging from +1.3 to +1.5. Essentially black desperately tries to activate, successfully manages that, but then white infiltrates the queenside and it all starts to slowly fall apart as b6 and c6 are weak and impossible to protect while maintaining enough activity to suppress white's kingside attack...
As to a proposal for an alternate mistake to blame, i'm not sure i'd be able to posit one. Just that your suggestion of o-o instead is hardly a cure leading to a simple draw - just a different inferior position that may or may not be holdable.
Black easily plays f5 after Nh4.
For example: Nh4 Be6 f4 Kh7 g4 f5
[d]r4r2/3qp1bk/1pp1b1pp/p1p1Pp2/P4PPN/1P1P3P/1BP1Q3/R4RK1 w - f6 0 6
As you see, black has
just played f5, with perfect equality.
White should capture now gf5 gf5.
Later black will include Rg8, Qe8, Bh8, Rd8.
Engines still show here some +80/90cps for white, but that is perfectly equal.
You should not look too much at engine evals, engines quite often go astray due to considering mobility where it should not be considered, or not considering other factors where they should be considered.
Concerning playing g5 right after white's Nh4, as I wrote, I did not check that at all, as I think Nh4 is a weak move.
But if I look at it now as an option, yes, I think g5 also draws.
It is true that engines show here some 120-130cps white edge, etc., but those are bogus scores. It is true white has better activity here, that is why the high engine score, because of mobility, but absolutely no winning/breaking through chances.
It is dangerous for white to move its king side pawns; d4 brings nothing, black constantly attacks a weak e5 pawns, so how does white break through?
For me, this is also a draw, and that is why I considered Nh4 weak.
As Carlsen says, he looks at moves suggested by engines, but does not pay too much attention to them.
Same with me, I look at engine evals, but am not too much bothered with them.
There are
200cps engine evals that are straightforward draws, and 50cps engines evals that are straightforward wins. I know how to distinguish between them. I would rather choose a 50cps winning eval than a 200cps drawing one.
I am glad Mr. Flesher supports you, that means I am on the right track.
