1.e4
e6
2.d4
d5
3.Nc3
Nf6
4.e5
Nfd7
5.f4
c5
6.Nf3
In round two, Short played dxc5 against Morozevich, and got into all kinds of trouble. Clearly he found no special improvement and goes back to one of the mainlines.
6...Nc6
7.Ne2
Be3 is the most common guest but Ne2 has already been played by Short more than once and it is unlikely Vallejo was unprepared.
7...Be7
8.c3
a5
9.h4
The main caveat of this move is that it assumes White's king is safe in the center without castling, or at the very least will compensate any risk taken by creating threats against Black's king. It is really not clear how this can be true after 0-0 and f6, opening the f-file and undermining the center.
9...0-0
10.Rh3
f6
11.a3
Rf7
12.Be3
Nb6
13.b3
Qf8
14.Qb1
a4
15.dxc5
Bxc5
16.Bxc5
Qxc5
17.b4
Qf8
18.Ned4?
Although a mistake, its refutation is a brilliancy that Nigel should be forgiven for missing.
18...fxe5!
19.Nxc6
19...e4!!
20.Nce5
Rxf4!
The point is that not only is black threatening f1 behind the knight, but the knight on e5 is actually trapped and has nowhere to escape to.
21.Nh2
Qf5
22.Neg4
22...Rxf1+
[The engine say that 22...h5!
was stronger, and while there is no doubting their analysis here, the line is really not obvious and one cannot blame Paco for shirking this choice even had he seen much of the idea. With so many possibiities at every move, simplicity was much preferable. 23.Ne3
Qf6
This move is the key as it pressures c3 and h4. The attack on c3 gains time now, but by freeing the c8-h3 diagonal, e5 will hit hard. 24.Qc2
e5
25.g4
Forced since Rg3 is countered by Qxh4. 25...hxg4
26.Rg3
Qxh4
27.Qg2
d4
And the combination of steamroller center with pieces tied up in knots is winning.]
23.Nxf1
Qxg4
24.Ne3
Qg6
25.Kf2
e5
26.Rg3
Qf6+
27.Kg1
Be6
28.Qe1
Rf8
29.Rd1
Kh8
30.h5
Qh4
This was the point Kh8, to be able to play this and not suffer a fatal discovered check with Rxg7+.
31.c4
d4
32.c5
Nc4
33.Nf1
Qxh5
34.Rc1
e3
35.b5
e4
It is all over needless to say.
36.Qb4
e2
37.Nh2
Qf5
38.Nf3
Qf4
39.Qe1
Qe3+
0-1