that is a spunky lil' black KB, i must say.

Nh4 is the most aggressive way to prevent Qg7# mate (Kxf8 = Rxb2), and the pawn captures f3 and g2 follow naturally.

after the Q exchange is refused with exf3, Qxf5 is forced to prevent Qb1+, c1+, d1#.

after fxg2+, Kg1 is forced.

after Bd4+, Qe2 is forced.

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I (black) am down a rook for a pawn, so I'll be needing to find some tactical maneuver to make things good.

I stared at this position for quite a long while before it dawned on me that white is threating Qxg2#! Noticing that you are about to be mated does help you to focus. What to do?

There's 32...Kxf7, but then my K is exposed to 33.Qd6+ Ke8 34.Ba4+ .

Most other moves (e.g. 32...Qg6, or 32...g6) allow 33.Qb8

The only move that's interesting is <32...Nh5>, since besides preventing Qg7#, it takes the initiative by attacking white's Q.

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Note that white can't play 34.Qb8 now due to 34...Ng3+!

- 35.hxg3 Qh5+ 36.Kg1 Bd4+ is a winning attack.

- 35.Qxg3 exf3! threating ...Qxb2+ and fxg2+

I figured that white, being up a rook, would try to trade down queens, with <33.Qg4>, but black can try to diagonally push the pawn: <33...exf3 34.Qxf5 fxg2+! 35.Kg1>

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Black has <35...Bd4+> now, but this is where I got stuck. Sure, white must play <36.Qf2>

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But capturing the queen is no good since white already took my queen, and I'd just remain severely behind in material.

I overlooked the very clever reply <36...Nf4!>

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Watch out for 32...exf3?? 33.Qxg7#. Therefore the first move has to be:

32...Nh5!
Attacking the Queen and defending g7.

If 33.Qg4, 33...exf3! 34.Qxf5 fxg2+ 35.Kg1 Bd4+ 36.Qf2 Nd4! 37.h4 (37.Qxd4 Nh3#) Ne2+ 38.Kh2 Bxf2 followed by g1=Q.

33.Qe1
Guarding the Rook.

33...exf3
34.Rxb2 fxg2+ and now

35.Kg1 Nf4 36.h4 Qh3

or

35.Rxg2 Nf4 36.Bb4 Bxg2+ 37.Kg1 Be4

Due to threat of Qxg7# we can discard all but 7 moves;

32 ... Qg6/Qg5 33 Qxg6/Qxg5
32 ... Ng4 33 Qxg4
32 ... g6/g5 33 Rxb2
32 ... Kxf8 33 Qd6+ mating!

<32 ... Nh5>

Okay we have survived losing instantly, but is this black's real objective?! Nope, black has a forced win after Nh5!!!

33 Qg4 exf3
34 Qxf5 fxg2+
35 Kg1 Bd4+
36 Qf2 Nf4!!! mating

So instead white must play for the win...

<33 Qb8 Ng3+!!>

Awesome, black gives up the knight as Bb2 is now protecting against Qxg7# White cannot refuse due to 34 Kg1 Bd4#. White cannot take with Ph2 due to a forced mate...

34 hxg3 Qh5+
35 Kg1 Bd4+
36 Kf1 Qh1+
37 Ke3 Qxg2+
38 Kd1 Qf1+ (Ke1 Qf2+ forces 39 Kd1 one move later) 39 Kd2 e3+! (Kc2 Qe2+ 40 Kc1 Bd3#)
40 Kc2 Qe2+
41 Kc1 Qd1#

So white must take with the queen. We are back where we started, but without a mate threat of Qxg7# as Bb2 is now protecting g7.

<34 Qxg3 ...>

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<34 ... exf3!>

35 Rxb2 fxg2+ 36 Rxg2/Qxf2/Kg1 Qf1#

35 Kg1 Bd4+ mating

35 gxf3 Bxf3+ mating

35 h3/h4 Qxb1+ 36 Kh2 fxg2! mating or winning the queen

35 Rd1 gxf2+ 36 Kg1 Bd4+ 37 Rxd4 Qf1#

35 Rf1 gxf2+ 36 Kg1/Qxg2 Qxf1#

35 Re1 gxf2+ 36 Kg1 Bd4+ 37 Qe3 Bxe3+ (Qf2 Qxf2#/Bxf2# or Re3 Qf1#) 38 Rxe3 Qf1#

<35 Rg1 fxg2+>

36 Rxg2 Qf1#

<36 Qxg2 Bxg2+>

37 Rxg2 Qf1+
38 Rg1 Qf3+
39 Rg2 Bd4 mating

<37 Kxg2 Qg4+>

38 Kh1 Qf3+ mating as above

38 Kf2 Bd4+

<31 Kf1 Qf3+>
<32 Ke1 Kxf8>

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The slaughter has begun...

~~~

37.h4 Ne2+ 38.Kh2 Bxf2 39.Bd6 g1Q+ 40.Rxg1 Bxg1+ 41.Kh3

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Komodo-10.1-64bit:

<-2.63/24 41...Nd4> 42.Bd1 Nf5 43.Ba3 Bd4 44.Be2 f6 45.Bb4 Kf7 46.h5 Be5 47.Bc3 Nd4 48.Bd1 f5 49.Nc1 Bf6 50.Nd3 Be4 51.Nc5 Bc2 52.Bxc2 Nxc2 53.Bxf6 Kxf6 54.Kg3 Ne3

But wow, I didn't believe that could work until I sorted out all the lines.

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Komodo-10.1-64bit:

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Komodo-10.1-64bit:

31...Nh5

32.Qg4 exf3! 33.Qxf5 fxg2+ 34.Kg1 Bd4+ 35.Qf2 Nf4! threatening mate. White must advance the h2 pawn to stop mate.

32.Qb8 Ng3+! 33.Qxg3 (33.hxg3 Qh5+ 34.Kg1 Bd4+ 35.Kf1 Qh1+ 36.Ke2 Qxg2+ etc.; 33.Kg1 Bd4#) exf3 34.Rxb2 fxg2+ and mate next.

33.Qxg3 transposes to my line above.

White threatens Qxg7#, Rxb2, Be7, Bb4, etc.

The only reasonable move seems to be 32... Nh5:

A) 33.Qb8 Ng3+ (33... Be5 34.Bd6#)

A.1) 34.Qxg3 exf3

A.1.a) 35.Rxb2 (or 35.Rf1) 33... fxg2+ and 36... Qf1#.

A.1.b) 35.Rg1 fxg2+ 35.Qxg2 (35.Rxg2 Qf1#) 35... Bxg2+

A.1.b.i) 36.Rxg2 Qf1+ 37.Rg1 Qf3+ 38.Rg2 Qxb3 39.Bd6 Qxa2 - + [Q+2P vs R] (40.Be5 Qa1+ 41.Rg1 Qa8+ 42.Rg2 Bxe5).

A.1.b.ii) 36.Kxg2 Qg4+ 37.Kh1 (37.Kf1 Qf3+ 38.Ke1 Qxb3 wins decisive material; 37.Kf2 Bd4+ wins) 37... Qf3+ transposes to A.1.b.i.

A.1.c) 35.gxf3 Bxf3+ 36.Kg1 (36.Qxf3 Qxf3+ 37.Kg1 Bd4#) 36... Bd4+ 37.Kf1 Qxb1+ 38.Qe1 Qd3+ 39.Qe2 Qxe2#.

A.1.d) 35.Rd1 fxg2+ 36.Qxg2 (36.Kg1 Bd4+ 37.Rxd4 Qf1#) 36... Bxg2+ 37.Kxg2 Kxf1 - + [Q+2P vs R+N].

A.1.e) 35.Bc2 fxg2+ 36.Qxg2 (36.Kg1 Bd4+ and mate next) 36... Bxg2+ wins decisive material.

A.1.f) 35.Nc3 Bxc3 seems to drop the knight for nothing.

A.2) 34.Kg1 Bd4#.

A.3) 34.hxg3 Qh5+ 35.Kg1 Bd4+ 36.Kf1 Qh1+ 37.Ke2 Qxg2+ 38.Kd1 (38.Ke1 Qf2+ just delays mate one move) 38... Qf1+

A.3.a) 39.Kd2 e3+ 40.Kc2 Qe2+ 41.Kc1 Qd2#.

A.3.b) 39.Kc2 Qe2+ 40.Kc1 Be3#.

B) 33.Qg4 exf3 34.Qxf5 (due to Qxg4 and Qxb1+) 34... fxg2+ 35.Kg1 Bd4+ 36.Qf2 Nf4 37.h4 (37.Qxd4 Nh3#) 37... Ne2+ 38.Kh2 Bxf2 will recover the rook and end up two pans ahead. For example, 39.Bd6 g1=Q+ 40.Rxg1 Bxg1+ (this would be mate if White plays 37.h3).

C) 33.Qe1 Ng3+

C.1) 34.Qxg3 exf3 transposes to A.1.

C.2) 34.Kg1 Bd4+ wins decisive material.

C.3) 34.hxg3 Qh5+ 35.Kg1 Bd4+

C.3.a) 36.Kf1 exf3 37.gxf3 Qxf3+ 38.Qf2 Qxf2#.

C.3.b) 36.Qf2 Bxf2+ (36... e3 37.Qe2) 37.Kxf2 Kxf8 - + [Q+P vs R+N].

D) 33.Qf2 exf3

D.1) 34.Rxb2 fxg2+ 35.Kg1 (35.Qxg2 Qf1#) 35... Nf4

D.1.a) 36.h4 Nh3+ 37.Kh2 Nxf2 wins.

D.1.b) 34.Qxf4 Qxf4 35.Rf2 Qe3 wins.

D.2) 34.Qxb2 f2 (34... fxg2+ 35.Kg1 Kxf8 -35... Nf4 36.Qxg7#- 36.Qa3+)

D.2.a) 35.Rf1 Ng3+ 36.hxg3 Qh5#.

D.2.b) 35.h3(4) Qh3#.

D.2.c) 35.Qe2 Qxb1+ wins.

E) 33.Qh3 exf3

E.1) 34.Qxf5 fxg2+ transposes to B.

Then 33 may digress in different paths.
A short one:

33.Qb8 threatens releasing B@f8 dis+, h6 (get a breather, no strong killing attack from Blk) 34.Be7 dis+ Kh7
35.RxB exf3
36.QxB f2
Then W runs out of effective defense, e.g.
37.g3 fails to f1=Q#, OR
37.Qf3 - same f1=Q+, Qxf1Q but QxQ and Blk is Q-less.

Then a long one:
32...........Nh5
33.Qf2 KxB
34.RxB exf3
35.gxf3 Bxf3
36.Kg1 Qg4+
37.Kf1 Qh3+
38.Ke1 Nf4
39.Be2 Ng2+
40.Kd2 Qh6+
41.Kc3 ....

Blk got the momentum, but WK may easily escape.....