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Black correctly figured that the bishop was immune, since 17.gxh3?? Nf3+ forks K+Q.

Of course, white wasn't about to fall for that, but it's not so clear that black thought through the consequences of what white *would* do. White responded with arguably the most logical move: kick the knight and then take the bishop! <17.f4! Ng6 18.gxh3>.

This does allow <18...Qxh3>, with the black queen picking up another pawn and approaching white's exposed king, and perhaps black saw this and the two pawns as adequate compenstation.

However, as ill-conceived attacks often do, it opened the door for a strong counter-attack: <19.Qb4+!> [diagram]

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A tight spot for black! What doesn't work:

- 19...Kg8? 20.Bxf7+! Kxf7 21.Ng5+ and it's black being hit with a K+Q fork.

- 19...Ne7? (removes threat on Pf4, allowing...) 20.Re2! (defending against Q check, thus freeing white to play Ng5 or Qxd4; also threatens to double Rs on e-file against black's pinned N)

Black's best is <19...Re7>, but then <20.Nf2!> hits the pinned R and buys time with an attack on black's Q. <20...Qd7> (guarding the R [*]) <21.Rad1 Qc8 22.Qxd4> [diagram]

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Black faces a bunch of threats on the back rank and on f7. White's Q+B+2R are all active and strong, and his extra N plays a big defensive role. Black's Q on c8 is on a hopeless defensive mission and his h8 rook is useless.