9..Nd7 was first played by Botvinnik in the mid forties; it is rarely played today. 10 Bg5, an idea of Furmans, was new. Botvinnik spent 40 minutes on 10..h6; he did not like 10..b6 11 e5 or 10..Qc7 11 Bxe7..re8 12 d5!..Qe5 13 d6. Bronstein and Levenfish each thought 13 Nf4 would have been stronger with advantage to White.>
This is played but rarely if ever on master level. More often after Nd7 the development is through b6 and Bb7.
14. a4 [not played in this game]
is a good intermediate move and I think it could be played as it removes the possibility of black passers later on in the game.
The most powerful continuation, almost certainly going to present huge problem for black is
[Bronstein's recommendation e5 is also fine]
15. ... Nf6
16. e5! [now the move Bronstein recommended preventing black counterbreak e5] Ng4 [the only sensible move to try to diffuse attack by removing bishop]
17. f5 gxf5 [...Nxe3 is not any better]
18. Bxf5 gxf5
19. Rxf5 cxd4
20. cxd4 Qb6
21. h3! [just in proper time forcing knight to exchange and opening vent for king]
and now while it is not immediately lost the black position is much, much worse than what had happened in the game.
I would label this position since I cannot find any satisfactory defence against white threats [immediate threat Qe4 and Rc6]
22. ...Kh8 [to avoid the x-ray]
23. Kh2! Qe6 [to protect f7 and control c8 for possible rook exchange after Rac8] 24. Qe4 Rac8
This is now becoming hopeless. Black can get two rooks for the queen but the attack continues with creation of d-passer [Taking pawn on a2 looks even more dangerous]:
26. Qxf5 Rxc1
27. e6 Kg8
28. Nd5 Re1
29. Nxe7+ Kh8
30. d5 fxe6
31. Qc2 Be5+
32. g3 Rf7
33. d6 Bxd6
and black loses material without any hope of any fortress. The knpp versus kpppp ending that can be reached is lost.