16.  B-R2         KR-Q1
17.  KR-K1        Kt-R4

This threatens B-B3 attacking the RP.  White decides to yield the same at once, thinking quite rightly that a direct attack must have good chances, as Black gets two pieces out of play in capturing the pawn.

18.  QR-Q1 B-B 3
19.  Q-Kt4

Black cannot take the pawn yet, because of KtxP and BxPch.

19. ...  P-B5
20.  P-Q5?

---------------------------------------
8 |    |    | #R | #R |    |    | #K |    |
|---------------------------------------|
7 | #P |    |    |    | #Q | #P | #P | #P |
|---------------------------------------|
6 |    | #P | #B |    | #P |    |    |    |
|---------------------------------------|
5 | #Kt|    |    | ^P |    |    |    |    |
|---------------------------------------|
4 | ^P |    | #P |    |    | ^Kt| ^Q |    |
|---------------------------------------|
3 |    |    | ^P |    | ^P |    |    |    |
|---------------------------------------|
2 | ^B |    |    |    |    | ^P | ^P | ^P |
|---------------------------------------|
1 |    |    |    | ^R | ^R |    | ^K |    |
---------------------------------------
A    B    C    D    E    F    G    H

Diag. 151

There is no need to play for violent complications.  The logical course was to open the way to the King’s side for the Rooks by P-K4.  The continuation could have been:  20.  P-K4, BxRP; 21.  Kt-R5, P-Kt3; 22.  P-K5, BxR; 23.  RxB followed by Kt-B6, with a strong attack; also after 21. ...  P-B3, 22.  R-Q2, White’s attacking chances are good.  After the move in the text, Black could get an advantage by simply exchanging:  20. ...  PxP; 21.  KtxP, BxKt; 22.  RxB, RxR; 23.  QxRch, R-Q1; 24.  Q-KB5, P-Kt3; 25.  Q-B2, Q-R6.  In taking the RP, however, Black incurs grave risks.

20. ...  BxRP 21.  R-Q2 P-K4 22.  Kt-R5 P-Kt3 23.  P-Q6 Q-K3 24.  Q-Kt5 K-R1

Black finds the weaknesses at his KB3 and KR3 very troublesome.  RxP would lose at once, because of 25.  RxR, QxR; 26.  Q-R6!

25.  Kt-B6 RxP
26.  RxR QxR
27.  B-Kt1

Q-R4 would have been answered by K-Kt2.

          27. ...  Kt-B3

Black must try to bring back his minor pieces for the defence.  If he succeeds in doing that in time, the end-game is easily won on the Queen’s side.

          28.  B-B5 R-Q1

Not PxB because of Q-R6.

          29.  P-KR4

White’s attacking resources seem inexhaustible.  By exchanging Queens he could have got his pawn back in this way:  29.  B-Q7, Q-B1 (R xB?, 30.  Q-R6); 30.  BxKt, BxB; 31.  QxQP, Q-Q3; 32.  Kt-Q7,QxQ; 33.  KtxQ, B-K1; 34.  KtxQBP.  But even then Black would maintain a superiority in the end-game owing to the freedom of his passed pawn, and because he can post his Rook at the seventh after P-QKt4.  This explains why Marshall prefers not to win back his pawn, but to enter upon a violent attack with a doubtful issue.  However, Capablanca finds the right move in all the ensuing complications, and finally wins the game.