Man, the Poisoned Pawn Is Hard to Play

This one drove me batty.  By the last move, I stared at the screen for half an hour (this was a daily game), found myself confinced I was lost, despite lots of ideas that seemed like they *almost* worked, then found an idea that I thought might actually work, and played it -- only to resign after remembering why it loses on the spot.  And of course the engine tells me that I had two different winning moves I could have chosen between, one of them a mate in twelve.  (And, naturally, this was a game where a win would have given me a shared victory in the tournament...)

The engine also assigns the game five "brilliant" moves between the two of us -- a completley meaningless metric that merely means the engine can't figure out what's going on in these positions either.  There are several places where it sits for ten or twenty seconds on "0.00" before discovering a mate in twelve or some such.

If you like failed mating attacks, enjoy!

never played the poisoned pawn before 

my first time seeing it

Okay, managed to make it work this time.  Even after I blundered a piece there was enough chaos left to find a nifty combination.

#1 Game.
Cheparinov (2696) vs. Roeder (2432) went 16. ... BxNd4

19. Bd6, impressive move.
21. Bh5, I pondered 21. Rf2 and 21. Qf2

26. Bxg6, 26. Bg4 as preparation for Qh6

29. Rd3 ?? Yeah 29. Rf1

29. ... Bd7 30. RxNg6 NxR 31. Qf8+ NxQ 32. RxN#
29. ... Qb4 30. Rg7-f7 Kg8 31. hmmmm

I had to check the engine, but there the win is through the amazing interference move c4-c5!!  If the bishop takes, it's mate on g7.  If the queen takes, there's no back-rank problem anymore, and white's got Rg7+ Kh8 Rxg6 Nxg6 Rf7.  I can't imagine how any human finds that though.

#6, 31. c5 as you point out since [c1] is covered by Qh6 wow !!
I was trying to defend f8 with the queen because as you know, remove the two black knights and white rook when it is Qf8# (or Rf8# since knight covers g7)

You can say that you're learning though - I think if you're only looking at lines that seem to bring total success, or lines that you fully understand - it's a bit bland.

I remember reading a bit from a GM Joe Gallagher, and he was talking about how flogging a dead horse line of (coincidentally) of the Najdorf actually taught him a lot - he knew it could win....but all the evidence and games he played seemed to be proving him wrong.

(I will did out the precise variation if anyone's interested - who knows, since the writing of that book it might have subsequently been discovered to be the best line!)

On move 18 you could have taken his queen

Hmm, not sure what you mean.  Do you mean move 19 of that first game I posted?  If so, unless I'm missing something, that can't be done without trading off my queen, which I wasn''t keen to do after sacrificing three pawns for the attack...

As for 19 Bd6, which someone else mentioned as a nice move, I wish I could take credit for it, but it's been played before. I think we left theory a couple of moves later.

And thanks, Boyd, for the encouragement.  At least it's interesting positions.

I know it is very late, but I must ask: what do you have prepared (in the second game) to 16... h3!? I've been trying to make that work out for White without compromising activity or forcing a book perpetual.

What does Black do after 8. a3?

Here is a recent correspondence game:
https://www.iccf.com/game?id=1360192

Likely either 8... Nc6 or 8... Nbd7.

It's a good question. The database only shows the perpetual you mention. I'll check my books tonight and see if any of them have any ideas for something better.

Nc6 is supposed to be best. The white knight retreats to b3, which usually, in these sorts of Najdorfs, means that Black is doing all right.

a3 is a much more critical variation in the delayed poisoned pawn, where White has already inserted h6 Bh6. The difference is that, instead of Nb3, White has Bf2.

My point is that the Poisoned Pawn is a fashionable opening typically played by Engine Kiddies, who owe most of their "chess knowledge" to memorized lines. How many of them have even encountered an anti-PP line? How many of them understand the resulting positions?

How many of them will even recognize that after 8. a3 Qxb2 loses the Queen?

... and there's nothing wrong with the 8. a3 lines as White. White's Knight has retreated, yes... but Black's Queen will need to move again. His Knight has lost touch with b6 and f6 (both available after Nd7 instead of Nc6). White can even look at playing Bh4 (heading for f2) without waiting for Black to play h6. That's an extremely strong plan in the French Tarrasch, for example.

It's true -- I've lost games (as Black) in the 8. a3 and (similar) 8. Nb3 lines. The fact that they're not the most critical approach doesn't mean they're not dangerous.

Is this also an option against the 12... g5 line?

It seems legitimate enough according to Stockfish.

Yes, 13. Bf2 is legit. If you want an extensive coverage both of this (13 pages) and of the 16 ... h3 variation (12 pages, covering three different options for white: 17. Qd3, 17. g3, and 17. Bg4), then you should chck out Jarmula's "The Najdorf Bg5 Revisited, Vol. 2 (Thinkers Publishing, 2021).

Too much to summarize, but it seems the variation is far from exhausted.