Eyal: This is a model game for "positional" play against the Sveshnikov (and is indeed presented as such in K.’s "Revolution in the 70s"...) – combining pressure on d5 and against the weak a5 pawn.
Some interesting comments/lines given by Kasparov:
As far as theory goes, he thinks that 15.Bc4 is more accurate than Bb5, and that Black in his turn should have played 15…Ne7 (as in the stem-game Smyslov vs Sveshnikov, 1977) instead of Bb7 – all revolving around the key d5 square.
18...d5 is met by 19.exd5 Nxd5 20.Nxd5 Bxd5 21.h3! f6 22.c4 Be6 23.Qxd8 Rfxd8 24.Rfa1 Rac8 25.b3 Rd3 26.Rb1 and the a5 pawn falls (26…Ra8 27.b4); 21.h3 is necessary because after an immediate 21.c4 Bb7 22.Qxd8 Rfxd8 23.Rfa1 Rd2 White has back rank problems - 24.b4 Rad8! 25.h3 axb4.
19…Qb6 threatens 20…Bxe4, attacking the bishop on b5 by discovery; 22.b3 stops …a4 – Black can’t play it immediately after 20…Bc6, because he has to spend a tempo defending the d-pawn.
22...Qb7 is met by 23.Nd5! (23.f3? d5! 24.exd5 Nxd5 25.Rxa5 Qb6 26.Rxd5 Bxd5 27.Bxd5 Rxd5 28.Qxd5 Qxe3+ 29.Kh1 Qxc3 and draw) 23...Nxd5 24.exd5 Bb5 25.Rxa5 Bxc4 26.bxc4, and even though White’s extra pawn is doubled, he has good prospects for making the c5 break.
24.h4 & 25.h5 gain space on the K-side once Black is completely on the defensive, and help White in the endgame that results after 28.Bd5! with the swapping of pawns and pieces. White gets a passed pawn on the Q-side, and then trades it for the opportunity to infiltrate Black’s position with his rooks.