Benzol: <ughaibu> Here are Bronstein's notes to this game from "The Chess Struggle In Practice".
After Black's 5th move P-B3
"White's development seems beyond reproach, but it is not flawless: he has not taken control of his K4, and Black makes immediate use of this to prepare P-K4 and P-Q4. Szabo prefers to exchange on his K5, but then Black gets easy play and even starts thinking about seizing the initiative".
After White's 11th move N-R4
"One of the characteristics of modern chess is the dynamic position in which, although the chances for each side may be determined, it is difficult to decide which of them has the advantage. Each player usually thinks he stands better, although at times one thinks he is worse.
The basic factor in the present struggle is Black's KP. Supported by the Queen and Rook it might easily get to K6. To counter this, White wants to disrupt the enemy ranks by Knight raids on the flanks. Black decides not to lose time retreating the Bishop because if it is exchanged his Knight will occupy a good post on QB4 and a diagonal will be opened for his QB; futhermore, his next move prevents the Knight on KR4 from retreating to B3. All this would repay the "sacrifice" of the King's Indian Bishop with interest".
After White's 13th move B-R3
"With the unequivocal threat of 14.B-B4; however, now Black has time to hide his Bishop, not only opening the Queen's way to QR4 but also accentuating the unfortunate position of White's Knight on QR4. After 13.NxB NxN 14.N-K3 the game would be about even, but now the initiative goes completely over to Black. Grandmaster Szabo is not satisfied with the bird in his hand and goes after the two in the bush, which soon fly away".
After White's 15th move B-N2
"Necessary because the threat to move the Knight from Q2 would have created an unpleasant pin on Black's QB1-KR6 diagonal".
After Black's 17th move Q-KR4
"Also strong is 17...PxP e.p. 18.PxP Q-Q5".
"In view of Black's positional threat of N-B4, B-R6, etc., White is practically forced to sacrifice his KP".
"The Black Queen sets out on a long and dangerous journey. Five Queen moves for one pawn is obviously unprofitable arithmetic for Black. But what can White accomplish during those five moves?".
"As it turns out, White has made one useful move, QR-Q1; as for the advance of the King-side pawns, that may be called rather more double-edged than favorable for White.
It must be added that Black could have managed his pieces even better; for instance, 19...N-B4 20.N-B3 and only then 20...Q-Q6. In that case Black's Knight would have stood actively on B4, his QB would have an open diagonal, and White's QB would have been temporarily deprived of QB3.
What conclusion can we draw from all this? That with good development it is not dangerous to spend a few moves to win an important pawn. It is necessary, however, to evaluate the position sensibly and to calculate all the variations exactly".
"Captivated by his plan to get as much advantage as possible from the position of White's Knight on R5, Black violates both requirements just mentioned.
The obvious 22...P-QN4 would force White to trade his most threatening piece, the QB.
The variation 23.BxN NxB 24.PxP Q-R4 seemed not clear enough to me and I decided to make some waiting move. Now ... P-QN4 really is a threat, but ...".
After 23.P-N5 P-N4
"Alas! Black must give up a Knight so as not to fall into a mating attack - 23...N-R4 24.BxB NxB 25.N-N4, and then with Q-B3 White takes full command of the QR1-KR8 diagonal. Knowing Szabo's ability to conduct a direct attack, I did not doubt the outcome of the game if I entered this variation. Now Black must continue the fight with the energy of desperation".
After 24.PxN B-B1
"The Bishop returns home without glory, it's horse lost on the way".