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

Diag. 158

17. ...  PxKt

If RxKt, White exchanges Queens and plays BxPch.

18.  QxB Q-Q7
19.  Q-Kt5 Kt-Q5
20.  Q-Q3

With an extra pawn White forces the exchange of Queens.  Black cannot prevent it, as 20. ...  QxKtP loses the Knight on account of 21.  KR-Kt1, and 20. ...  Q-Kt5 loses the QP by 21.  KR-Q1 and B-K6ch.

20. ...  QxQ
21.  PxQ KR-K1
22.  B-Kt4

KR-K1 would not prevent the entry of the Black Rook:  Kt-B7; 23.  RxRch, RxR; 24.  R-QB1, R-K7; 25.  B-Kt4, R-Q7.  Black would win the pawn back and might even succeed in the end-game with a Knight against a Bishop.

22. ...                  R-Q3
23.  KR-K1               RxR
24.  RxR                 R-QKt3

Black should first play his King to KB3, and keep the Rook away from his K5.  Not that the QP is of paramount importance; the QKtP fully makes up for its loss.  But as played the Knight is driven from his dominating position, and the badly placed Bishop gets into play.  No doubt even after the text move the ending is most difficult, and it requires Rubinstein’s full powers to bring it to a successful issue.

25.  R-K5 RxP 26.  RxP Kt-B3 27.  B-K6ch K-B1 28.  R-B5ch K-K1 29.  B-B7ch K-Q2 30.  B-B4 P-QR3

Black’s only chance is his extra pawn on the Q side.  To exchange the Kt for the B by 30. ...  K-Q3; 31.  R-B 7, Kt-K4; 32.  RxKKtP, KtxB would take too much time where time is all-important.  White would clear the K side in the meantime, push on his KRP, and ultimately give up his R for Black’s remaining P, as soon as the latter runs into Queen, after which the three passed pawns win easily against the Rook.  Generally speaking it is wise, in R endings like the present one, to advance pawns on the side where there is an extra pawn, in order to get a passed pawn as soon as possible.  Then the hostile Rook has to look after that pawn lest it should queen, and the greater mobility of one’s own Rook often saves the game even when opposed by a preponderance of pawns.