Concentration till the End

I try to teach my students how to avoid the mistakes of my poor experience, and to save them precious time. This recent game reminded me of some of the most common ones that I did:
Lupulescu,C (2608) - Abasov,N (2397)
Victor Ciocaltea Mem Bucharest ROM (6), 28.03.2009

29.Rf6!! What made White discover this move? Let us try to follow his thinking process. [White is a pawn ahead, and he has more active pieces. Various tactical ideas can be seen for him. The first one is the weak eight rank: 29.Qf7!? (Not 29. Qf5 because of 29...g6 30.Qe5+ Bg7) 29...g6 30.Rd8 Black must defend with only moves- 30...Qa3 (30...Rxd8 will either lose both rooks or lead to mate as in the line- 31.Qf6+ Kg8 32.Qxd8+ Kf7 33.Bd5+ Kg7 34.Qe7+ Kh8 35.Qf6+ Bg7 36.Qd8+ Bf8 37.Qxf8#) White is at crossroads, should he win a second pawn with- 31.Qf6+ or should he better proceed with the development- (31.Rfd1!

This option is in fact much better. Bringing more forces into the attack is never a mistake. Even the tricky computer move- 31...Qd6!? would not save Black- 32.Qxh7+ Kxh7 33.R8xd6 Rxc4 34.Bxg6+ Kg7 35.Rxa6+-) At the same time the win of the second pawn makes White's task more difficult- 31...Bg7 32.Rxf8+ Qxf8 33.Qxa6±

True, he emerged two pawns ahead. However, the presence of the opposite coloured bishops, active black pieces, and last but not least-the fact that black king is now in safety should make us abandon this line. I missed many wins like this in my life. Remember, when you realize your advantage there is always a moment in which you must calculate precisely the win till the end. Any prolonging of the battle increases the possibility of your further mistakes.

Another interesting tactical idea is: 29.Rxh6?? With the idea to pick up the rook in case of- …29...gxh6 (However, this rushy continuation may cost you a well deserved win, since White's back rank is also weak. The cold shower- 29...Qxf2+!!

30.Rxf2 Rc1+ 31.Rf1 Rfxf1# will follow. We must never forget that the opponent has his own, creative ideas!) 30.Qe5+; Finally, we reach the move made in the game. It is both attacking and prophylactic, excluding the Black's counter attacking options. 29.Rf6!! gxf6 30.Qxh6 Rf7 31.Bxh7 White's attack is enough to take back the material with interest- 31...Qa3 32.Be4+ Kg8 33.Qg6+ Kf8 34.Bd5 Qe7 35.Rb1 Rb3!?

36.Qh6+ Kg8 37.Bxf7+ Kxf7 38.Qh7+ Kf8 39.Qxe7+ Kxe7 40.Rxb3+-] 1–0