Tigran Petrosian vs Iosif Pogrebissky (1949)

Notes by Peter ClarkeIn the last few years this fianchetto has lost ground as a means of combating the King’s Indian, being replaced by systems involving a more immediate and aggresive occupation of the center. Petrosian’s part in this trend is clear to see in later games. Here, of course, White may have been prepared for the Gruenfeld anyway.The basic idea behind Black’s play, as in the Alekhine Defence, to provoke his opponent into making premature pawn advances. Inevitably there is a considerable element of risk in such a policy, for nobody can predict the outcome with certainty and pawns which prove weak in one game may, given some new finesse, become a crushing force in the next. All this is typical of the modern approach to the openings -a willingness to make concessions of some sort in the belief that real counter-chances will be obtained in return.8...Nb6 went out of favour with the game Botvinnik - Novotelnov, Chigorin Memorial Tournament, 1947, which continued 9.d5 e6 10.Bg5 f6 11.Be3 Na6 12.Nc3 Nc4 13.Bc1 e5 14.Nb5 Bd7 15.a4, etc.Tempting fate a little too far. He should play 9...Nd5, to which White normally replies 10.dxc5, with an intense struggle ahead. A very useful opening principle refers to the danger of moving the same piece twice before completing one’s development. In this game Black’s whole strategy has so far been a negation of this - yet it cannot be condemned as wrong - and now White ’errs’ as well. Knowing principles is good; knowing how to break them is better! The Knight move is the only way to obtain the advantage. It fulfill two functions; permits him to consolidate his e-pawn by f4 and at the same time threatens the disruptive e6.He has no choice. After 10...e6 11.f4 White has secured his spatial advantage and Black’s play has failed accordingly.Too slow now. 11.e6 gives excellent chances; for instance, 11...Ne5 12.exf7+ Nxf7 13.Qb3 e6 14.Bxb7 Bxb7 15.Qxb7 Nxg5 16.Bxg5 Qxg5 (though 16...Qb6 is better, White still has the upper hand after 17.Qxb6 axb6) 17.Qxa8 Qb5 18.Na3 Qxb2 19.Qxa7 Nc6 20.Qd7 Ne5 21.Qxe6+ (Donner-Bouwmeester, Munich, 1954).If 11...Nc6 (reckoning on 12.e6 Nc5 13.exf7+ Kh8!) White could probably get away with 12.Bxc6 bxc6 13.Qxd4, the initiative and command of the center being his.This is really the decisive moment. White realises he must play with the outmost vigour-having failed to do so on the previous move! His idea here is that after 12...Ne6 (not 12...Nca6 13.a3!) 13.Nxe6 fxe6 Black’s KB would be shut out of the game for good while his other one would be a little better off. And the d-pawn would be sure to fall. So what is Black to do? He must play vigorously himself and instead of ...fxe6 be ready to sacrifice the exchange by 13...Bxe6 14.Bxb7 Bd5; if he accepts, White is left desperately weak on the white squares. Petrosian, who pointed out this possibility afterwards, would probably have exchanged Bishops and tried to make something out of the temporary isolatin of the d-pawn. The likelyhood of his succeeding would not appear to have been very great. But Pogrebyssky panics and in a vain attempt to drive back the enemy Knight gets his King position compromised.Defending the d-pawn indirectly, e.g. 17.Bxc6 Qxc6 18.Qxd4 Bh3 19.Rf2 Rad8, etc. However, since there was not that much to lose now, he might have boldly played 16...Bf5 and hoped for some counterplay if White took the pawn. By this energetic thrust White shows up the true weakness of his opponent’s K side. Though Black has got all his pieces out, they are powerless to stop the onslaught.Seeming to block the way, but White has a small combination ready.If 22...Qxf5, then 23.Qb1! forces Black to expose himself to a deadly discovered check; while if 22...Kh5, there is the drastic finish 23.Qxg4+! Kxg4 24.Rf4+ and mate next move.The quiet point. Petrosian concludes the attack with a series of elegant strokes. An echo of a previous idea; if 25...Bxd1, then Rh4+ Kg5 27.Bc1 mate.Threatening mate in two by Qh2+.1-0