Ulhumbrus: 15 Qh5 makes what is in fact in fact a double attack . It attacks the Black KB on g5 directly but also- and this is less less obvious- it attacks the e6 pawn indirectly by pinning the f7 pawn and so threatening f5xe6 as well as Qxg5. On 15...Qd8 instead of playing 16 fxe6 at once, Bronstein delays this by the skewer 16 Rg1! attacking the Bg5 again and the g7 pawn behind it.
This induces 16...h6 defending the Bg5 again but also weakening the g6 pawn and exposing the 7th rank to attack, and only now does Bronstein play fxe6. The choice of 16 Rg1! instead of 16 fxe6 at once can be called, for this brief moment in the game, a miniature lesson in attacking play.
On 26 Rc6! instead of 26 Rb6 induces 26...Rfc8 which blocks this square for the attacked B on f5. Now on 27 Rb6 The black QB cannot go to c8 and 27...Bd7 invites the skewer 28 Rd7 in reply, and 27...Bd8 does not help as on 28 Rd6 Be7 29 Rd4 Black's QB is still short of squares. Another small lesson in attacking play.
27...Rxc3 looks like an act of desperation, seeing no other way to save the Black QB. Bronstein declines to recapture the Rc3 but takes the B on f5 instead, starting an attack on the point g6 with tempo, as Black's R is attacked on c3. 29 Bd3 delays a capture on g6 and instead develops the KB towards the attack on the b1-h7 diagonal. This is another small lesson in attacking play.
Whereas Black can do nothing useful in reply, the move Bd3 increases the power of the attack in addition to developing the B, so it does more than Black's reply which does nothing useful.
The 31 a4 delays the thrust f6 in order to remove the threat of a back rank mate by ...Rd1. Then 32 f6 resumes the attack and once again Browne offers the exchange by 32...Rxd3, seeing no other way to answer it. Once again Bronstein declines the offer and continues the attack by 33 Rg7+ Kh8 and Bronstein delays the capture cxd3 to threaten mate instead by 34 Rh1! threatening 35 Rxh6 mate. After 34...Be3 35 cxd3 White threatens Re7 as well as f7. Browne resigned at this point.
As well as being entertaining, this game contains several small lessons in the art of attacking play.
One lesson given twice in the game is to delay a recapture in order to threaten something which then extracts a further concession from the opponent Thus Bronstein delays 16 fxe6 by 16 Rg1 in order to threaten the Bg5 by 16 Rg1, extracting the concession of 16...f6. He delays 26 Rb6 by 26 Rc6, extracting the further concession of 26..Rfc8. He delays the recapture
Another lesson, given twice, is to decline material and play an attacking move instead. Thus instead of the recapture 28 bxc3 Bronstein plays the attacking move 28 exf5 and instead of 33 cxd3 he plays the attacking move 33 Rg7+.
Another lesson is to delay a recapture in order to play a move which does more than to develop if the opponent has nothing useful in reply. Thus 29 Bd3 delays a recapture on g6 in order to do more than to just make a developing move with the Bishop, as the bishop makes a contribution to the King side attack as well. Black has, it seems, no useful reply.
It occurs to me that this game is packed with instruction as well as being entertaining. To repeat what Seirawan said, this was played by a 65 year old man against an expert in the Najdorf.