Gilmoy: A dazzling <zwieschenduel>, with both players trading "in-between" mate threats, tactical shots, and body blows. A GM's margin of victory over a fellow GM is sometimes razor-thin -- you offer him a mate-in-two to set up your mate-in-one. Pack ice into your hat brim.
<15..Nh5> looks book-theoretical in Spanish -- Black bravely opens his Kingside, seeking the mythical skin-side of the razor. <16.Nc3> White doesn't fear 16..Nxg3 17.hxg3 g4 18.d5, when Black has given up his best K-side defender, has no real pressure, and big weaknesses at g6/h6. <16..g4?!> 1st zwiechenzug, weakening d4. <17.e5> 1st zwieschenposte, offering pawns to press Black's K-side weaknesses: 17..gxf3?? 18.Qg6+ Ng7 19.Ne4!! will cost the Queen or mate at h7.
<18.Bh4 Nb4> 2nd zwieschen-pair, with <mutual threat> to the Qs. <19.Qb1> maintains a grip on g6/h7. White plans Ra3 regardless, a thematic transfer to K-side in a4/cxd4-lines of Spanish. <19..f6> as Q(e8,d7) 20.Ne4 is too painful: Black offers up an exchange, hoping for 21.Bxf6 Qxf6 22.Nd2 Bxd4, defusing all White pressure with a huge K-side attack of his own -- Bb7-Rg8 must win by force. White saw that coming, and <21.Nd2 d5> 3rd zwieschenzug, with threat of Ne4+ momentarily saving his d4-pawn. Black must snuff it, White trades down, <22..Nxf6 23..Nh5> Black coughs up two precious tempi to keep his own d5-pawn.
<27.Nfg3> White abandons his weak d-pawn to hammer Black's K-side. <29.Bf5!> clearance-sacs his f2-pawn to create another avenue of attack (for both sides!!) -- White's Re7(+) looms, and Black's Qf2 is momentarily harmless. <32..Qd2> defends h6 <33.Ra3> for 34.h3 <33..Rf8 34.Nh4> a diabolical trap!? <34..Qc2> defends g6 <35.Qe1> not-weak back rank and 36.Qe5+ <35..Bd4 36.Ra1!!> reinforced back rank frees his Q to sortie once without check -- he sees all the long-diagonal tricks.
<36..Bxb2 37.Rd7!!> opening the a3-f8 diagonal. Black has a problem: he has a free Rook in one, and weak-back-rank mate in two -- but it's not a mate-in-two, and the missing tempo means White wins by checking first. White has a problem: he's hanging a Rook on faith that he has a winning cascade of mate-in-one threats. If he's wrong, he loses -- that's the margin, ask waiter for more ice! The Rook is briefly untouchable because Black has <weak long diagonal> (hah!); meanwhile, White has 38.Qxb4 with <mutual threat> to Rf8, and not-weak-yet back rank. <37..Qe4 38.Qf2!!> and Black has <weak back rank> of his own -- meanwhile White just forked Bb2 and Rf8, so one must move to defend the other, and as Rf8 has zero southward mobility: <38..Bg7> and White can breath: <40.Qxf7> and now Bxa1?? <Q sees h7> 41.Ng6+ is one way to fix a weakness!
<42.Rf1> is the final piece of the puzzle: Black has three pawns, but White has Qe8-Rf7 pinning the Q, with Black's K still trapped, or chasing her down with a discovered check if she runs.