In Diagram 128 the favourite continuation for many years was:  7. ...  BxKt; 8.  PxB, Kt-K2.  The opening of the KKt file by 9.  BxKKt is not to be feared, because of the reasons given when discussing Diagram 90.  But White obtains the advantage with 9.  Kt-R4, preparing the opening of the KB file by P-B4 and PxP. 9. ...  Kt-Kt3, in order to retake with the BP after 10.  KtxKt and to open the file for Black’s Rooks, is not a sufficient reply, because after 11.  P-B4 and PxP White has a clear advantage, having an extra pawn in effect for the end-game.  For the three Black pawns on the King’s side are held by the two adverse pawns, which they cannot pass.

The attempt to expel the troublesome Bishop after 9. ...  Kt-K1 by P-KB3, and then play for a centre by P-B3, Kt-B2 and P-Q4 fails on account of the withering attack which White obtains on the KB file, e.g. 9. ...  Kt-K1; 10.  B-QB4, K-R1; 11.  P-B4, P-KB3; 12.  Q-R5, PxB; 13.  PxP, etc.

In consequence the defence by 7. ...  BxKt and Kt-K2 has been abandoned.

In the present game Black reverts to a very old defence, comprising the moves:  BxKt, Q-K2, Kt-Q1-K3.  It had been abandoned because White, by playing R-K1, P-Q4, and eventually B-B1 and B-R3, forces the exchange of Black’s centre pawn, and obtains an advantage, on well-known grounds.  Here Black strengthens the defence by interpolating P-KR3!, after which White must come to a decision as to maintaining the pin.  If he decides to do so the White Bishop will no longer be able to threaten the Black Queen from QR3.

          7. ...  BxKt
          8.  PxB P-KR3
          9.  B-KR4

If the B retreats to B1 or K3, Black can adopt the defence Kt-K2- Kt3.  Then Kt-R4 would be inferior, because Black can simply play P-KKt4.  In this case the advance of the pawns is justified, because Black can bring his QKt to KKt3 and have practically one piece more on the King’s side, and good prospects for the attack which he can open with K-R2, R-KKt1, Kt-Kt3-B5.

9. ...  Q-K2

P-KKt4 would be premature.  White would win at once by 10.  KtxKtP, PxKt; 11.  BxP, as he can attack the Knight a second time by P-KB4 and PxP before Black can either protect it sufficiently or relieve the “pin.”

10.  Q-Q2 Kt-Q1 11.  P-Q4 B-Kt5 12.  Q-K3 BxKt 13.  QxB Kt-K3

It would be wrong to play for the gain of a pawn with P-KKt4 and PxP, e.g. 13. ...  P-KKt4; 14.  B-Kt3, PxP; 15.  R-K1!, PxP; 16.  P-K5, etc.

14.  BxKt

Black’s threat was to develop an attack, similar to that described at move 9, with P-KKt4 and Kt-B5.

14. ...  QxB
15.  QxQ PxQ
16.  B-B4

in order to exchange the Knight, which is generally superior to a Bishop in an end-game, as mentioned before.