I don't get this game. Black misses the pretty obvious 39...Rxh3+, winning easily, but finds the difficult 42...Qb6.

The material is even, but the position is decidedly unbalanced. White has two passed pawns on the queen's side of the board, and black has an attack on the white king underway.

My first thoughts concerned getting the black queen to the 8th rank and coming in behind the white king to deliver checkmate. Something like...

41...Rxg3 42 fxg3

Not 42 Rxg3 h4 winning the pinned rook.

42...Qb6

Threatening 43...Qg1#. I think white must now play

43 g4

Playing 43 Rh4 does white no good after 43...Qg1+ 44 Kh3 Qh1#.

43...Qg1+ 44 Kg3 Ra3+ 45 Kf4

Not 45 Kh4 g5+ 46 Kxh5 Qb1 and white can't stop the queen from delivering mate on g6 or h7.

45 Qd4+ Qe4 46 g5+ Kf5 47 Qd7+

and it's all over but the shouting. I think this is it, time to check.

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First, I decided White has almost no moves in this position. Neither rook can move, nor the king. At the beginning of my analysis, I was trying to see if there is a way to set up a zugzwang, but I couldn't find one.

Then the idea of maneuvering the g4 rook to the back rank started to look interesting. So, I was thinking 41...Rxb4 followed by ...Rbb1. This works spectacularly well in the continuation 41...Rxb4 42. a7 Rbb1! 43. axb8=Q Rh1#. But, alas, after 41...Rxb4 42. Qxh5 is very annoying, since after 42...Rbb1 42. Qh6+ White mates first.

So, that's how I decided on 41...Kf8 -- I can't let White escape with that Qxh5 trick. With the king on f8, White has no useful checks or mating threats. From here, the moves I considered for White were:

a. 42. Qf3 Rxb4 43. a7 (43. Qxf6 Rbb1! 44. Qh8+ Ke7) Rxh7. Unfortunately, after 43. h7 Black can't play ...Rbb1 immediately because the pawn promotes with check. However, since White can't do anything active, I think Black can grab the pawns and then return the rooks to the first rank.

b. 42. f3 Rxb4 43. a7 Rxh7 should work the same as line a.

c. 42. a7 Rxa7 again should work like line a, with Black lining up his rooks on the first rank while White can't do anything constructive.

d. 42. b5 Rb4! 43. a7 Rxa7 44. Rxh5. If there is a line where White escapes by taking the h-pawn, this has to be it. But, it clearly doesn't work: 44...gxh5 45. Qxh5 Qxb5 leaves Black a rook up.

e. 42. Qb2 Rxa6 43. b5 (Quite fortuitously, 42...Rxa6 also prevents Qxf6.) Raa4, planning ...Rgb4 to get the rooks to the first rank.

41 ... a4 looks tempting but W is fine after 42 Qxg4.

Therefore 41 ...Rxg3, a killer.

If 42 a7 then ... Rxh3++ 43 Kxh3 Rh1#

If 42 fxg3 then ... Qa7 and W is defenceless against Qb1

If 42 Rxg3 then ... h4 43 a7 hxg3+ 44 Kh3 Qh8+ 45 Kxg3 or 43 Kh3 hxg3. W has other tries but I cannot see a way to avoid dropping at least a R.

However, White's back rank is too weak. This suggests 41... Rxb4 42.Qxh5 (threatens 43.Qh6+ Kg8 44.Qh8#; 42.a7 Rbb1 - +)

A) 42... Qxg3+ 43.Rxg3 (43.h(K)xg3 gxh5 - + [R+P]) Rbb1 44.Rxg6+ (otherwise 44... Rh1 mates or recovers the queen with a rook up) fxg6 45.Qe2 with probable draw.

B) 42... Kf8 43.Qh8+ (43.Qc5+ Kg7(8) 44.Qh5 repeats moves) Ke7 44.Qxb8 Rxb8 45.Ra3

B.1) 45... Rxa3 46.Rxa3 and the white king will march to the center creating the double threat of supporting the passed pawn and invading Black's king side.

B.2) 45... Rf1 46.a7 Ra8 47.Rhb3 Re1 48.Rb8 Re8 49.Rxe8 + -.

B.3) 45... Re1 46.Rhe3 (47.a7 Ra8 47.Rhb3 Re7) Rd1 (46... Rxe3 47.Rxe3 is similar to B.1) 47.a7 Ra8 48.Re7 followed by Rb(c)3 and Rb(c)7 with advantage.

E Sedina vs M Hoffmann, 2010 (41...?)

Black to play and win.

Material: Even. The White Kh2 is stalemated. The Black Qb8 pins Rg3 to Kh2. The White Qe2 attacks Rg4, a burden, because otherwise Ph5 could advance and play …hxg3. Alternative support for Rg4 by 41…f5 42.Qb2+ (winning Ra1) is not immediately available. White handily wins the endgame with Q and Rs because of his connected passed Pa6 and Pb4. The Black is secured from check.

Candidates (41...): Rxg3

41…Rxg3 42.fxg3 [Rxg3 h4, winning Rg3]

42…Qb6 (threatening 43…Qg1#)

(1) 43.Rxh5 Qg1+ 44.Kh3 Qh1+ 45.Kg4 Qxh5+, winning Qe2

(2) 43.g4 [Rh4 Qg1+ 44.Kh3 Qh1#]

43…Qg1+ 44.Kg3 Ra3+

(2.1) 45.Kf4 Qd4+ 46.Qe4 g5+ 47.Kf5 Qd7+ 48.Qe6 Qxe6#

(2.2) 45.Kh4 g5+ 46.Kh5 Rxh3+ 47.gxh3 Qg3

This forced capture and reply (i.e. 41...Rxg3!! 42. fxg3) allows Black to play 42...Qb6! with a winning pursuit and mate combination.

The sequence that follows is practically forced through 44...Ra3+, and if White tries to vary with 45. Kf4 then it's mate-in-three after 45...Qd4+ 46. Qd6+ Qe5 47. Qxe5#.

P.S.: The combination that appears to turn the game almost decisively in Black's favor is the double pawn positional sham sacrifice 33...a5! 34. bxa4 b4! to .

One possible improvement for White is 32. Rfe3!, since 32...Rxc3? 33. R3e6 to is practically winning and other tries seem to give White easy equality. Also, better than 33. Qe4?! is 33. Rg6 =.

BTW, 42...Qxb4 also wins decisively, although not as impressively; it's fun to play out.

click for larger view

2) white was temporarily " down " two rooks. The g3 rook was pinned. The h3 rook was stuck on the h-file hammered in by the white king and the other rook. The h3 rook did have an prophylactic measure of preventing h4 push and supporting the mating threat of Qxh5 if the g4 rook moved.

3) White king was stalemated while black king was safe hiding behind the kingside pawns wall. The doubled f-pawn helped with the defense but creating passed pawn out of them was a difficult task.

4) black could maybe lose the momenteum by capturing the b4 pawn

5) black would really like to put more pressure on the pin with h4 push if possible. He also wanted to double rooks along the eighth rank when both the white rooks were still tied down

6) Black could try mobilizing his kingside pawns to create further weaknesses in white camp. They could also help in the king hunt.

candidate: Rxg3