Abdel Irada: <<•>Once more unto the breach....<•>>
Dear friends, the war-blast has blown. 'Tis time, then, for our parfit gentle knight to imitate the action of the tiger, by his sacrifice teaching the enemy how to war.
And so it begins:
<<•> 37. Nf6†! ...>
Nor can the sacrifice be refused, though Black close the wall up with his Old Indian dead. The proof:
(a) 37. ...Kh8? 38. Rd8 .
There is no surviving this. To take the rook is to be mated; not to take is to lose his own.
<<•> 37. ...gxf6
38. exf6 ... >
To save the rook or not to save it? Black has four answers to consider.
<(1) 38. ...Ree8/Rc7
39. f5! >
This was the real point of the knight's sacrifice: Now, with a foot-soldier on f6 leading the charge across the battlements, the queen threatens a fatal incursion on h6.
All the defenses fail:
(a) 39. ...Qg3? 40. Rg4†, winning the queen.
(b) 39. ...Bd5 40. Qxh6, Bxg2† 41. Kh2!, leaving no follow-up check and no further way to delay the mate on g7.
(c) 39. ...Kh7 40. Rh4, and again mate is ineluctable.
<(2) 38. ...Rd7>
Black hopes to restore the balance by offering back a bishop, but White need have none of it.
<39. f5! >
Again this breach is lethal.
(a) 39. ...Rxd4 40. Rxd4, Bxf5 41. Qxh6, Qxg3 42. Rg4†! and mate is imminent.
(b) 39. ...Bxf5 40. Qxh6, Qxd1† (40. ...Qxg3 41. Rg4†) 41. Kh2! and again there is no defense.
(c) 39. ...Bd5 40. Qxh6, Bxg2† 41. Kh2!, winning as before.
<(3) 38. ...Bd5
39. fxe7, Bxg2†
40. Kxg2 >
White has a rook plus a far-advanced passed pawn for an errant knight. The battle is over.
<<•>(4) 38. ...Qxg3!?
39. fxe7, Bxh3
40. Rg1! >
Against so determined a siege, no defense will hold.
(a) 40. ...Bxg2† 41. Rxg2, winning the queen.
(b) 40. ...Kh8 41. exf8=Q†, winning easily by preponderance.
(c) 40. ...Kh7 41. Be4†, winning the queen.
Having disguised fair nature with hard-favour'd rage, White must win through, and all credit is due a knight modest, still and humble in peace, but whom the fortunes of war have lent an eye of terrible aspect.