Pogonina vs Chess.com Move 24.
The Alliance have been talking about opposite coloured bishops and the pawn sacrifice 24.Bg4. giving loooong variants. I had no clue whatsoever what they were talking about. Bg4 was somewhat foreign to me. Looking more deeply into the position, very long and shaky variants, arriving at move 35-40 !!! I found some substance to the talk about opposite coloured bishops. If those positions are a natural conclusion of 24. ...Bxg5, then 24.Bg4 has a point: avoiding the drawish R+B/R+B endgame. Let's assume those impossibly long lines are correct and Pogonina also has tuned in on it. It is not, however, the only move to avoid the bishop exchange.
Candidates: (Some of the starters for Bg4 are "stolen" from the Alliance.)
A) 24.Bg4 Nxe4 (24. ... Qxe4 25.Bf5 Qxc2 26.Bxc2 +) 25.Bb6 Rd7 26.Bd3 (26.Bf3 f5 [26. ... d5 27.Rxd5 ] 27.Ra4 d5 28.Qb3 Nf6 29.Bxd5+ Nxd5 30.Qxd5+ Qxd5 31.Rxd5 Black is somewhat passive and White has more space but fairly even. ) Nf6 (26. ... d5) 27.Bf5 and so on as in the Be2-line
B) 24.Be2 Nxe4 (24. ... Qxe4 25.Bf5 Qxc2 26.Bxc2 +) 25.Bb6 Rd7 26.Bd3Nf6 27.Bf5 Rdd8 28.Bxd8 Rxd8 Black has only a pawn for the quality but has the centre pawns e5/d6. White's rooks is out of good lines to work on. Given the closed or semi closed character of the position I would rate the knight somewhat higher too. It's a fairly even position if Black is good at piece play and has a sense for dynamics. Over the board and face to face ... I don't know.
On the whole 24.Bg4 is not more promising for White than 24.Bxg5 which I analyzed in move 23.
For those of you who do not have the time to flip back:
a) 24.Bb6 does not seem to work because g7 is a strong black square. Opening the g-line gives White nothing. 24. ... Nxf3+ 25.gxf3 Rcc8 26.Kh1 f5 27. Rg1 Kh8 =,
b) 24.Bxg5 Bxg5 We have opposite coloured bishops but it is not really important since all the heavy pieces are left. If on the other hand one side gets initiative the difference in colour controll could be interesting. 25.Ra4 Going for b6/b7. 25. ... g6 Giving the king some air and placing pawns on the colour that obstructs White's bishop and does the opposite for Bg5. 26.Rb4 If the rook gets to b6 it also adds pressure on d6. Maybe b5 is necessary here? Let's try passive first.
b1) 26. ... Qc5 27.Qa4 Rd8 28.Rb6 Re7 29. Rd5 Qc7 30.Qb4 + All white heavy pieces are bearing down on d6. So let's look at an aggressive approach.
b2) 26. ... b5 27.axb6 Rb7 28.Be2 Rxb6 29.Rxb6 Qxb6 30.Bc4 a5 31.g3 + Well all those lines look nice for White.
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