1.d4 Nf6 2.c4 e6 3.Bg5 Not the most common move here but one which has been played by many highly rated players such as Avrukh and Bauer. More often White develops one of the knights when the specific opening that results is still uncertain.
3...d5 Black plays a move that leads to a Queens Gambit set up. Other frequent choices include [3...Bb4+ 4.Nc3 with a Nimzo-Indian.; 3...c5 4.d5 b5 a Blumnfeld gambit. (or 4...exd5 5.cxd5 d6 with a Benoni system) ; as well as 3...Be7 ; and 3...h6 when play can lead to a Torre Attack or Classical Queens Gambit Declined.]
4.Nf3 [If 4.Nc3 then one possible continuation is similar to the main game and also transposed to the Queens Gambit Declined (Exchange variation) 4...Nbd7 5.e3 c6 6.cxd5 exd5 7.Bd3 Be7 8.Nf3 0-0 9.0-0 Re8 when White usually plays the move 10.Qc2 reaching a well known tabiya favoured by players of different styles such as Timman, Karpov, Kramnik and Aronian. (Instead a less pointed continuation was 10.Nh4 aiming for Nf5 but allowing Black to free his game immediately with 10...Ne4 as in Bell-Donnelly, Teesside Ch 1970.) ; Avoidance of transposition to the major openings listed earlier with 4.e3 is a solid option but eventually led to some problems for White after 4...c5 5.Nf3 cxd4 6.Nxd4 Qa5+ 7.Nd2 Ne4 8.N4b3 Qb6 9.Nxe4 dxe4 10.Qd4 Bb4+ 11.Kd1 in Crutchlow-Donnelly, Coventry League 2003.]
4...Nbd7 5.Nc3 c6 6.cxd5 Avoiding Black's intended opening- the Cambridge Springs Defence. This opening did occur in Westra-Donnelly, Yorkshire v Cheshire and N.Wales, Rotherham 1976 and continued [6.e3 Qa5 7.Qc2 Bb4 8.Nd2 0-0 9.Bxf6 Nxf6 10.Bd3 Re8 This position has been reached many times before this game by other players and has been played often afterwards too even though Black has no especial opening problems.]
6...exd5 Yielding the Queens Gambit Exchange Variation. Instead [6...cxd5 can be played here, for example, as in Kramnik-Mamedyarov, Tal Memorial Blitz, Sochi 2014. However, in the standard move order that reaches the Exchange Variation, White plays cxd5 before Black has had a chance to play c6 so the line does not occur that often in praxis.]
7.e3 Be7 8.Bd3 0-0 9.Qc2 Re8 10.0-0 Nf8 11.Ne5 White has numerous options at this junction of the game. The one chosen is possibly the most agressive aiming for a kings-side attackvia supporting the knight with a subsequent f4.
11...Ng4 [11...Nh5 doesnt look as good as after 12.Bxe7 Rxe7 13.b4 White has an edge as in Lilienthal-Lundin, Salsjobaden 1948.]
12.Bxe7 Qxe7 13.Nf3 [13.Nxg4 Bxg4 14.Rae1 Rad8 gives Black even chances as has occurred in many games.]
13...g6 [13...Ng6 is another way to play the position as, for example, in Kempinski-Korobov,CZE T-ch 2011.]
14.h3 Nf6 15.Ne5 [15.Rab1 a5 slowing b4 16.Na4 is the "Minority Attack" way to proceed but Black seems fine after 16...Ne4 ]
15...N6d7 16.f4 This seems the most logical supporting the advanced knight although the move does leave the e3 pawn weak. Perhaps surprising, is that here, the exchange [16.Nxd7 has often been played by strong players when White may opt after the capture 16...Bxd7 for central play with 17.Rae1 (or queens-side play with a Minority Attack introduced by 17.b4 a6 18.Na4 Ne6 19.Nb6 Rab8 20.Rab1 Byrne-Mednis, USA-ch New York 1963.) 17...Ne6 18.f3 Atalik-Rogozenko, ROM-ch Sovara 2003.]
16...f6 17.Ng4 f5 [17...h5 is another way to chase the knight but does weaken the kings-side somewhat. Hence White may sacrifice the knight, instead of the bishop as in the main game, with 18.Bxg6 (18.Nf2 is solid but doesn't cause problems for Black after 18...f5 (but not 18...Qxe3 19.Bxg6 and Blacks kings-side is wrecked with White also able to get a rook to the seventh soon following 19...Rd8 20.Bxh5 Qxd4 21.Rae1 so White is easily winning.) 19.Rfe1 Nf6 20.Bf1 Ne4 21.Nd3 Ivanov-Filippov, RUS-T ch Sochi 2004.) 18...hxg4 19.Bxe8 Qxe3+ 20.Qf2 Qxe8 21.f5 Hlavica-Olivera, GER-op Rd 1 E-mail 2008.; 17...Nb6 decentralises the knight and White is better after 18.f5 (18.Rae1 Bxg4 19.hxg4 Kg7+/= Tarasov-Ananskikh, RUS-T ch sf E-mail 2009.) 18...g5? 19.e4+- Volkov-Ahlander, Lund Cellavision Cup 2017.]
18.Bxf5?! Played by banging down the bishop on f5 and knocking the pawn off the board. This move aims to blast open Black's king-side and use a pawn avalanche to generate an attack. The sacrifice was not really expected by Black hence some time was now used to analyse the position in detail to try and find a way to hold back the impending pawn storm. [18.Ne5 was the expected move when White controls e5 with a bit more space but Black can aim to contorl e4 with 18...Nf6 (18...Nxe5 has been played in an earlier game but is promising for White, for instance, 19.fxe5 Be6 20.Rf3 Nd7 21.Raf1 Rf8 22.Qf2 a6 23.Ne2 c5 24.h4 with a powerful attack as in Hermann-Rellstab, West Cologne 1935.) ]
18...gxf5 19.Qxf5 Ng6 The defensive plan commenced with this move allows Black to harass the White queen with Rf8 then develop the queens-side. This seems the most straightforward way to keep an advantage. [Harassing the queen with 19...Nb6 is also possible but then the position becomes a little murky after 20.Nf6+ (as well as after 20.Nh6+ Kg7 21.Qg5+ Qxg5 22.fxg5 Be6 23.b3 ) 20...Kf7 21.Nd7+ Kg7 22.Qe5+ Qxe5 23.Nxe5 In each case it's not immediatley clear how Black will capitalise on the material advantage of a bishop for two pawns.]
20.Rae1 [20.Qh5 making way for f5 can be met by 20...Nf6 (but not 20...Ndf8 as disaster strikes Black with 21.f5 Nh8 22.Nh6+ Kg7 23.f6+ and the queen is lost.) 21.Nxf6+ Qxf6 22.f5 Qh4 23.Qf3 Rf8 24.g4 and the pawns are held back and Black can continue with b6/Ba6 or Nh8-f7 with a clear advantage.]
20...Rf8 21.Qh5 [If 21.Qc2 Black can side-step the threat of e4 with 21...Qg7 (21...Nf6 is here not very good as after 22.f5 Nxg4 (or 22...Nh4 23.e4 ) 23.hxg4 Nh4 24.e4 White's pawns are becoming threatening and he has more than adequate play for the sacrificed bishop.) 22.f5 this can be met with the counter-strike 22...h5 which returns the extra pawn to achieve great piece activity and a winning game via 23.fxg6 hxg4 24.hxg4 Nf6 25.g5 Ng4 ]
21...Nf6 Again simplest. Black forces the exchange of a dangerous attacking piece. Alternatively [21...Qh4 22.Qg5 Qxg5 23.fxg5 Kg7 24.e4 is not so clear cut as White is fully developed and controls the important f6 and h6 squares.]
22.Nxf6+ Qxf6 23.f5 Ne7 24.g4 Bd7 25.e4 Despite being the best option this further sacrifice fails, due to a later pin, which allows Black to grab more material. Another move which leads to very similar play is [25.g5 which gains a tempo for advancing the pawns but leaves the f5 pawn under attack. For example 25...Qd6 (25...Qg7 is also feasible but not quite so strong as f5 is not so weak. Black's idea would be to blockade the pawn after 26.f6 with 26...Qg6 forcing 27.Qxg6+ Nxg6 ) 26.e4 dxe4 27.Nxe4 Qxd4+ 28.Rf2 Rxf5 29.Nf6+ Qxf6 30.gxf6 Rxh5 31.Rxe7 Bxh3 32.f7+ Kf8 preventing the pawn from queening and leaving Black a clear piece up.; Note that if White plays a line that prevents Qxd4 as being a check, so still trying to achieve e4, then Black has a sneaky retreat available. For example after 25.Kg2 Be8 traps the queen and forces 26.g5 Bxh5 27.gxf6 Rxf6 and White has nothing but a lost game.]
25...Qxd4+ 26.Rf2 Rae8 Completing development and indirectly pinning the e4 pawn against the e1 rook.
27.g5? White was by now very pressed for time and makes a serous mistake. However, after both the following lines Back can make a counter-sacrifice on f5 to emerge with a winning ending: [27.Qg5+ Qg7 28.Qxg7+ Kxg7 29.e5 Nxf5 (29...Bxf5 is also more than good enough 30.gxf5 Rxf5 31.Rxf5 Nxf5-+ ) 30.gxf5 Rxf5 31.Rxf5 Bxf5-+ ; 27.e5 Nxf5 28.gxf5 Rxf5 29.Qg4+ Qxg4+ 30.hxg4 Rfxe5-+ ]
27...Nxf5 [With 27...Nxf5 White's game collapses, for example, if 28.g6 (or 28.Rd1 Qc5 29.g6 again loses to 29...Qxf2+ (and Black even has the idea of 29...Nh6 30.Qxh6 Qxf2+ 31.Kh1 Qf3+ 32.Kh2 Re7 which also wins.) ) 28...Qxf2+ 29.Kxf2 Ng7+ recovering the queen and leaving Black a lot of material up. Alan explained after the game that he didn't want the current one to end in a draw in the manner of our previous 3 encounters. In each he had been under pressure, but with hard work and usually ending up in severe time pressure, had managed to salvage a half-point. In the current one he admitted he tried to hard to win. I should add the late Alan Sayers wrote a very high standard Chess Column for the newspaper "The Sunderland Echo" for many years. He also played a major part in the organisation of the British Championships in that City in 1966, and promoted chess in that area of the North-East, as well as for Sunderland Chess Club also for many years. Despite all these commitments he was a very strong player too, with a BCF grading of around 190-200, at a time when that really meant something.] 0-1