White’s compensation for the pawn consists in his control of the square e5, and his pressure on the open files and the long diagonal. In one move, Black changes the character of the struggle.
He loses after 26.Nxa5 Bd6!, whilst in the event of 26.Nd2 Rae8, White has no positional compensation for the exchange, since his knight has lost the strongpoint c4. Black is ready to set his pawn center in motion, by first kicking the white rook with ...Bc5-d6.
Now, White has a small material advantage, but his position is bad, as Black has obtained control of the centre and an extremely strong protected passed pawn, only a short step from promoting.
White has a protected passed pawn on d5, typical of the Grünfeld Defence. The further White can push it, the greater his threats, because the Bg7 does not hold up the pawn’s progress. But there is a danger – the moment the pawn moves forward, it ceases to be protected by its own pawn, and the enemy pieces can try to surround and capture it. In this example, White manages without a sharp advance of the pawn.
30.f4! Qg4 31.Bxh8 Qd1+ 32.Bf1 Nd6 33.Qh3+ Qh5 34.Qc3 Ne8 35.d6! Qd1 36.Qh3+