I have spoken here before of "intuition born of experience." When one sees a position of this kind, in which a crucial pawn is defended only by a king, and numerous hostile pieces are bearing down on its vicinity, a sacrifice comes immediately to mind. And when that square is f7 or f2 (statistically the squares more sacrificed on than any others), it might as well sport a billboard reading "SACRIFICE HERE."

Therefore we begin:

<26. ...Nxf2!<>>.

White must make a decision: to accept the sacrifice or decline it and look for something else to do. In this case, the sac isn't forcing; there are no immediate threats, and White is free to ignore it if he chooses. On the other hand, unless he can find a way to win back a pawn, he will be left a pawn down and with a further weakened king's field.

As it happens, there's only one target for White: the pawn on c5. So, as a practical matter, White can either take this pawn or accept the sacrifice and see if he can refute it. Any other choice is too passive.

Let us, then, examine these choices respectively.

<(1) 27. Qxc5, Qxc5
28. Rxc5...>

Here, Black would like to take advantage of the "pinned" e-pawn with ...Nd3, forking the rooks. Unfortunately, the pawn isn't really pinned because the rook on e1 is defended. So, what if we remove the guard?

<28. ...Bxf3>

This presents White with what <Once> would call a "GOOT": "Get Out Of That!" If he takes on f3 with the pawn, the rook on e1 falls with check; if with the bishop, 29. ...Nd3 wins the exchange.

But what if White takes the knight?

<29. Kxf2...>

Now, if Black plays the obvious 29. ...Bxg2, White's choice looks good: He will recapture on g2 with complete equality. However, Black has a stronger choice.

<29. ...Bxe2†
30. Kg1, d3
31. Rd5, Rd8 >

And suddenly the passed pawn looms as an implacable menace. White is only a pawn down ... but what a pawn!

Now, let's see what happens if White takes up the gauntlet.

<(2) 27. Kxf2, Qe3†
28. Kf1, Bxf3
29. exf3...<>>

White can also take with the bishop, but this makes no difference, for it will only transpose.

<29. ...Rxf3†!
30. Bxf3, Qxf3†
31. Kg1, Qxg3†<>>

Another move, another decision. Should the king run towards the wing or the center?

We will consider these options in order.

<(2.1) 32. Kh1...<>>

This is the safer course because no obvious mating attack ensues. But this does not mean it is *safe*; one can lose without being mated. Nonetheless, I will consider it the main line because it offers White his best practical chances.

<32. ...Rxe1†
33. Rxe1, Qxe1†
34. Kg2, Qxh4
35. Qxc5, Qe4†
36. Kf2, d3 <>>

Thanks to Black's queen position, White has only one check, so perpetuals aren't possible as long as Black remains cautious. Meanwhile, Black is three clear pawns ahead, and the passed d-pawn is once again very dangerous.

Having seen that White can't genuinely "survive" running to h1, we now test the idea of moving toward the center and trying to hold.

<(2.2) 32. Kf1?!, Rf8†
33. Ke2, Rf2†
34. Kd1, Qf3†
35. Re2, d3 >

Back to the starting position ...

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... and it strikes me that there is a similarity between this position and at least one of the earlier POTDs. We have a choice of two knight sacs followed by Qe3+ invasions. We can play either 26...Nxg3 or 26...Nxf2. In either case, the f pawn disappears and we get a chance to squeeze the large lady into f3.

But 26...Nxf2 is much stronger because it limits white's reply. Here's the position after 26...Nxg3 27. fxg3 Qe3+

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Now, if white plays 28. Kf1 we've transposed right back into our game line. White is in huge trouble. But the white king is far enough away from the black queen that he has some more options. He can run to h1 or h2, and the white attack stutters. After 28. Kh2, Fritzie says that white has a small advantage of around +1.3. In other words, the knight sac hasn't worked.

By contrast, after 26...Nxf2 27. Kxf2 Qe3+, we get to here ...

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The pawn structure is exactly the same. We've got the same Qe3+ motif. But the key difference is that the white king is forced back to f1 where he comes under fire from the black Rf8 and Ba8. He doesn't have the option of Kh2.

Well, not unless white were to cry out ... "Good lord, look at that!" and while black turns to see what all the fuss is about white shunts his king to h2. Less subtle than iphones in toilets, I supppose.

I wonder if this leads us to a general rule of thumb (or two). If given a choice of two sacrifices we should usually prefer the one which gives our opponent fewer replies. And/or it's usually better to sacrifice close to the enemy king - eg on f2/f7 rather than g3/g6 or h3/h6.

26 ... Nxf2
27 Qxc5 Qxc5
28 Rxc5 Bxf3

But here I think white takes back with the bishop
trapping the knight and going the exchange down
but with drawing chances. <29 Kxf2> loses even quicker!

29 Bxf3 Nd3
30 exd3 Rxe1+
31 Kg2 Ra1
32 Be4 Rxa3

The positions is okay for black, but not completely won...

***A position with hidden potential. No immediate, forcing move for Black is evident [ie: a check]. Whats good for Black is White does not directly threaten any capture or check, or even a sacrifice (For example, in the Wed POTD Z Necesany vs V Zagorovsky, 1972 White has counterplay if he's allowed to play <Rxe6+>)

Before we look at candidates, We can eliminate any "butcher"-type moves. Here, 26...Rxf3 doesn't work due to 27.exf3 pinning the Black Knight.

One candidate involving the Black Knight comes to mind: <26...Nc3> hitting <e2> 3-times; Black will chase the White Queen with <Bd5> and attempt to cut off communication between the White Queen and <e2>.

Lets see if this works:

<26...Nc3> (Other Knight moves like 26...Nf6 or 26...Nd6 allow 27.Qxc5)

The only response I see for White is <27.Rc2> which just seems horrible after <27...Bd5 28.Qd3 Be4> and Black wins at least an exchange:

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Black has two winning options after White's 29.Qd2 (forced): (1) <29.Qd2 Bxc2> gaining the exchange or

(2) <29.Qd2 Bxf3 30.Rxc3> (If 30.Bxf3 Rxf3 31.exf3 Qxe1+) <30...Bxg2>

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All black pieces are ready to attack the white castle, starting with 26... Nxf2:

A) 27.Kxf2 Qe3+ 28.Kf1 Bxf3

A.1) 29.exf3 Rxf3+ 30.Bxf3 Qxf3+ 31.Kg1 Qxg3+

A.1.a) 32.Kf1 Rf8+ 33.Ke2 Rf2+ 34.Ke1 Qf3+ 35.Re2 d3 36.Kd2 (36.Qe6 Rxe2 - +) 36... Rxe2+ 37.Kc3 d2+ wins.

A.1.b) 32.Kh1 Rxe1+ 33.Rxe1 Qxe1+ 34.Kg2 Qc3 - + [3P].

A.2) 29.Bxf3 Rxf3+ 30.Kg2 (30.exf3+ Qxf3+ transposes to A.1) 30... Rxg3+ and mate soon.

A.3) 29.Bh3 Bh1+ 30.Bf5 Rxf5#.

B) 27.Qxc5 Qxc5 (27... Qe3 28.Qxd4, unclear) 28.Rxc5 Bxf3

B.1) 29.Bxf3 Nd3 wins the exchange - + [R vs B].

Now, on (26. -Nxf2) 27. Qxc5 follows 27. -Qxc5 28.Rxc5 Bxf3 29. Kxf2 (29. Bxf3 Nd3 wins the exchange) -29. -Bxe2+ dis.ch. 30. Kg1 d3 and Black has a winning position.

If <26...Nc3>

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then <27.Rxc3 dxc3 28.Qxc3>

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I found this line, also mentioned in part by <agb2002>, to be the most aesthetically pleasing.

Here's the position after 31 Rd5.

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It's a bit awkward because black's bishop is pinned. But the doubled rooks are the answer. 31...Rd8 forces and simplifies nicely; it goes 32 Rxd8 Rxd8 33 Kf2 d2 34 Kxe2 dxe1Q+ 35 Kxe1 Rd3.

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And, if after 31…Rd8 white tries 32 Re5?!, black has 32 …Bg4, keeping the bishop safe and in control of d1.

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piece to have when managing a grand strike ah a8 e7queen lightning

and thunder swoop in e3 after kingxf2 ok ethereal 27.qe3+ only one

square tomahawk f1 then pile in four mitigate in bolt ba8xf3 pawne2

having recapture oak rookf8 i re work it down in dig off f3+ bishop

recapture coffins right sealed "eagle" knight it took in concrete

symbol line crashing for f2 either e3xf3+ now ledger in bull gate

kingg1 13...Qxg3+ king sidestep back time rook frollics in f8 one

potent it brew in e4 to f2 establish it a leg off in crick him aint

bothered in nervous moments white could infuse mister king stays

pitted in g1 so, homily for c5 d4 hangers white mind to gathers

27.Qxc5+ easy for hunk down exchange qe7 of a fashion to derelict

28.Rxc5s sandwich in arranging 28...Bxf3 29.Bxf3 nd3 and I alive to

fork it is e1 in c5 winning the re1 rumbled on gather in giving

mainline on gauge h1 then cocked in e8 grabs e1 wave effect wangle

in black three alive pawns up healthy lead in promoting either d4 or

eminate trace in c5 too finish him off tin king gets queen and rook

Black to play (26...?) "Very Difficult"

I didn't find this too tough... or so I thought! In under five minutes I thought I had it solved, but then I noticed something that I had to reexamine.

26...Nxf2! 27. Qxc5

This is the move I had missed. Easier to evaluate is 27. Kxf2 Qe3+ 28. Kf1 Bxf3 29. exf3 Rxf3+ 30. Bxf3 Qxf3+ 31. Kg1 Qxg3+ 32. Kh1 (or 32. Kf1 Rf8+) Re4 with ...Rxh4+ and mate to follow. Now if 27...Qe3 28. Qxd4 and White is defending adequately.

27...Qxc5! 28. Rxc5

It's counter-intuitive to trade queens in the middle of an attack, but this not only buys a tempo to save the knight and d4 pawn, but removes a defender of the e1 rook.

28...Bxf3! 29. Kxf2

If instead 29. Bxf3 (not 29. exf3 Rxe1+) Nd3 wins an exchange.

However, instead of 36...dxe2??, Black forces mate with <36...Rf1+ 37.Kd2 Qxe2+ 38.Kc3 Qxc2 mate>