On the St. George gambit, S21 SuFi g17-18

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Laoshi Ma

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Jul 28, 2021, 5:18:06 PMJul 28
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I set up an IDeA tree with the book exit as root. Nothing exhaustive, just on the order
of 1000 2-minute tasks (i.e., engine calls to SF dev), amounting to 1~2 days on a nice
Ryzen 5900 laptop to explore some variations.  Not everyone will agree for sure, but
based on this, it looks to me as if SF played this opening about as well as could be
expected--both times. After this exercise, the minimaxed book-exit eval was +0.90,
with a slow but clear downward trend.

Yes, Leela let out a sigh of relief when SF as White played 7. Ne2 not Qe2. But playing
the queen just transposes back to Leela's line as White--no wonder she prefers it.
In that line (i.e., game 17), you could deviate with 14. Be4 to keep queens on a bit
longer--also draw. Or deviate a bit later with 17. Bc4, and give Black a good scare
by placing white rooks on both b7 and e7 in one line--but it's still a draw. Or instead
deviate earlier with 9. g3 -- also drawn.

What does it mean to play an opening which is not busted? You pick a line, and in
that line you test the opponent as best you can. Didn't SF more-or-less do this? It
kept queens on, and really tried to make something of the a-pawn. It's just that
Leela was absurdly confident she could hold this line, which turned out to be true.

Yes, the book exit looked scary for Black, with White having the centre and a plus
pawn, but it seems the positions are just open enough that engines now know
how to defend them. Somehow the opposite of the 6. ... b5 Tarrasch (games
25-26, will try to do those next), where Black's troubles are apparently bigger than
most of the chat appreciated. Anyway I better leave the chess to others, I'm just
an engine jockey.

Pity that the Ceres-KD bonus was suspended just before this opening! Ah well, we'll
get it eventually I guess. Though if the analysis holds up, the main question would be
if Komodo can defend as accurately as these two giants. If there is a way to access
Navratil's games in this opening please let me know; a video stream is a hopeless
interface as far as I'm concerned.

Laoshi Ma

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Aug 7, 2021, 5:59:38 PMAug 7
to FishCooking
OK now Ceres and KD have also played this opening. Unfortunately, already on their
2nd out-of-book move with black, both strayed from the optimal path (at least
according to my tree, which admittedly will be biased to the SF eval function because
that is how it was created). Ceres at least found the 2nd-best move and still drew
with black; KD picked the 3rd-best move and lost. Seems the simple recapture
5. ... axb5 still is best.

Bottom line, these two more recent games don't really affect the above analysis of the
book-exit position.
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