The first move I looked at is

29...e3

This move seems like a real natural, in that, a) the pawn was threatened with capture, b) the move now threatens the white rook and, c) it cannot be captured (30 fxe3 Nxg3+ 31 Kf2 Ne4+ picks up an exchange).

I think white must respond with

30 Rc2

Now black gets to play

30...exf2

On the knight, and also threatening 31...Nxg3+.

31 Kxf2 Rf7

Threatening 32...Nd4+

White has two moves here to save the rook:

- 32 Rcc1
- 32 Rcd2

Moving the king either allows the rook fork via 32...Ne3 or drops the g-pawn with check. After that black can bring the rook on d8 to either e8 or h8 to take advantage of the naked white king.

I'm not sure how this ended, but I feel good up to this point.

But the move played (33...Nd4+) picks up a whole rook!

click for larger view

If white now played ♔xe3, black would deliver an unusual mate by ...♖e7:

click for larger view

Just to cover the bases Nf3 does nothing due to Rxf3+ and the full Rook drops. Kg1 Rf1++. After Ke2 Re8! sets up more shots. Again attempts to block the file with Nf3 just drop the Knight to Rxf3 with the same threats. Rc2 Nc4++. So Rd1 has to go somewhere. Ra1 Nc2+. Rb1 or Rc1 and Ng2+ Kd1 Rxe1+ Kc2 and now Ne3+ forces Kb3 when Rxb1(c1) Kxc4 again leaves Black up a ful Rook.

We start with a tense battle for d3. Black is firing doubled rooks and a pawn at the backward d3 pawn. White is hunkered down with doubled rooks, back rank knight and Ke2 to defend. Think Michael Caine in Zulu, trying to defend Rourke's drift against an overwhelming force.

I just couldn't break down d3, no matter how many silly moves I looked at. Nxg3 doesn't work, because the f2 pawn defends. c4 allows d4. ed releases the tension and allows white to unbottle.

Okay, if we can't kill d3, can we just go around it? Aha - 29...e3. Now on 30. fe we have Nxg3 and on 30. Rc2 we have either ef or we could shift rooks onto the e and f files. The fork square on e3 beckons.

And here I started to get lost with the different possibilities, but black seemed to be fine in all of them. So I was happy to go for 29...e3 and work out the variations OTB.

Here's part of the unplugged position.

click for larger view

White is defending the d3 pawn, but his position is horribly cramped. The d2 rook in particular has very little mobility. White would dearly love to free his position with d4, d5, d6 etc all the way to 1-0.

Black's main tactic in this position is to pile up on d3, doubling his rooks behind it and throwing in pawns and minor pieces. But if that doesn't work, he can try other strategies to exploit the cramped nature of white's defences, such as hitting the d2 rook or shifting the attack across a file or two to hit the misplaced Ke2.

A) 30.fxe3 Nxg3+ 31.Kf2 Ne4+ .
B) 30.Rc2 exf2
B.1) 31.Kxf2 Rf8 (threatening 32... Nd4+)
B.1.a) 32.Kg1 Ne3 .
B.1.b) 32.Ke2 Re7+ 33.Kd2 Ne3 .
B.1.c) 32.Rcd2 Ne3+ 33.Kxe3 Re7#.
B.1.d) 32.Rcc1 Ne3+ 33.Kxe3 Re7+ 34.Kd2 Rf2#.
B.1.e) 32.Re2 Nd4+ .
B.2) 31.Ng2 Rf8
B.2.a) 32.Kxf2 Nd4+ .
B.2.b) 32.Kf1 Nxg3#.
B.2.c) 32.Rf1 Nxg3+ .
B.2.d) 32.Ne3 Nxe3 33.Kxe3 f1=Q .

I briefly looked at 29...exd3, but this simply relieves white's tension and crampedness.

However, 29...e3! turns up the heat by forking Rd2 and Pf2.

White hardly wants to play 30.Rc2, allowing 30...exf2 31.Kxf2. This puts his king in a vulnerable position and leaves Pg3 hanging. It might continue 31...Rf7 which threatens both (1) an exchange-winning discovered check or (2) an exchange winning N-fork at e3. White can't avoid it: e.g. 32.Ke2 Re8+ 33.Kd2 Ne3+ .

Analysis by Rybka 3 1-cpu 32-bit: 16 ply time 6min 5 sec

1. (-2.65): 29...e3 30.fxe3 Nxg3+[] 31.Kf2 Ne4+[] 32.Kg1 Nxd2[] 33.Rxd2 Rh8[] 34.Re2 Rh3 35.b4

2. = (-0.09): 29...exd3+ 30.Nxd3[] Rd6 31.b3 Rf8 32.Re1 Re8+ 33.Kd1 Rxe1+ 34.Nxe1 Kf6 35.Kc2 Rxd2+ 36.Kxd2 Nd6 37.Kd3 Ke5

D Marotti vs W Schoenmann, 1928 (29…?)

Black to play and win.

Material: Even. The White Ke2 has 1 legal move. The Black battery Rd8 and Rd7 faces the White battery Rd1 and Rd2, obscured by Pd3. The White Pd3 is not pinned to Rd2, but Ke2 is burdened with Rd2. The Black Nf5 can give check, whereas the White Ne1 passively defends Pd3. The Black Kg2 is secure.

Candidates (29…): Nd4+, Nxg3+, exd3, e3

29…e3

Black is attacking the base of the White P-chain. Feasibly, White can take Pe3 or move Rd2:

(1) 30.fxe3 Nxg3+ 31.Kf2 Ne4+

White drops an exchange because Pd3 is now pinned.

(2) 30.Rc2 Rh8 (threatening 32…Rh2 and then …Rd7)

Black has no good defense against the invasion of the 2-nd rank.

(2.1) 31.Ng2 Rh2 32.Nxe3 [Rg1 Rd7] Rd7

and Ph2 pins Pf2 whether or not Ke2 moves.

(2.2) 31.fxe3 Rh2+ 32.Kf1 Nxe3+

White drops a N.

<[Toga rates the difference between 30…Rh8 and 30…exf2 at about 0.3 P.]>

Black to play (29...?) "Difficult" (3 stars)

My first impression was that the only move to really consider (i.e. the only candidate move) is 29...e3! This is based on opening lines to the White king, without allowing White's rooks to get active. Also, the pawn on e3 becomes very strong, and immune to capture.

After 29...e3!, there are only two options:

a) 30. fxe3 Nxg3+ 31. Kf2 Ne4+! 32. dxe4 (else White loses the exchange anyway) Rxd2+ 33. Rxd2 Rxd2+ 34. Ke3 Rxb2 and Black wins easily;

b) 30. Rc2 Rh8! (stronger than Re8 or Re7, but exf2 also wins), threatening 31...Rh2 -- and now:

b1) 31. Ng2 (fxe3?? Rh2+ 32. Kf1 Nxe3+ 33. Kg1 Rxc2 loses a knight) Rh2 32. Nxe3 (or Rg1 Re7 33. Rc1 exf2+ 34. Kxf2 Re3! 35. Rd1 Rf3+ 36. Ke1 Rxg3 37. Rd2 [Kf2 Rhxg2+ 38. Rxg2 Rxg2+ 39. Kxg2 Ne3+] Nh4 38. Kf1 Nf3 wins the exchange) Re7! and 33...Nxe3 will kill, regardless of whether White moves his king or not, i.e. 33. Ke1 Nxe3, and the win of a knight plus an exchange = a whole rook!

b1) 31. Kf1 (or Rcc1 Rh2 32. Kf1 e2+! 33. Kxe2 Nxg3+ 34. Ke3 [Kd2 Rxf2+ 35. Ke3 Re2#] Re7+ 35. Kd2 Rxf2#) exf2 32. Kxf2 (or Rxf2 Ne3+) Rf7! and White has no good move to avoid either Nd4+ or Ne3(+), e.g. 33. Rcd2 Ne3+! 34. Kxe3? Re8#, or 33. Ke2 Rh2+ 34. Kf1 Ne3+, winning a knight as in note b1).