This weekend the Candidates tournament commences in Berlin to decide the challenger who will face Magnus Carlsen for the world title in London later this year. The favourite is Shakhriyar Mamedyarov, with a rating of 2814, and this week’s puzzle shows a sample of his trenchant style. Although he is not the highest-rated, my money is in fact on triple Olympiad gold medallist Levon Aronian (2797), who is capable of reaching great heights when on form. The rest of the field, in rating order, is as follows: Vladimir Kramnik (2800), Wesley So (2799), Fabiano Caruana (2784), Ding Liren (2769), Sergei Karjakin (2763) and Alexander Grischuk (2767).
 
Aronian-Short: Gibraltar Masters 2018; English Opening
 
1 c4 e5 2 Nc3 d6 3 Nf3 f5 This early advance of Black’s f-pawn demonstrates that the British grandmaster was in an aggressive mood. 4 g3 Nc6 5 d4 e4 This response is the natural reply to White’s break in the centre. 6 d5 Ne5 Also possible is 6 … exf3 7 dxc6 bxc6 8 exf3 when White has slightly better prospects since he will be the first to occupy the e-file with a rook. 7 Nxe5 dxe5 8 g4 (see diagram 1) Not only does White lose a tempo with this advance he also potentially disrupts his own king’s flank. 8 Bh3 is more sedate and more normal. 8 … Bc5 9 Qb3 Nf6 10 Qb5+ Nd7 11 h4 Played not so much as to launch an attack but to prevent the black queen from landing on h4. 11 … a6 12 Qb3 e3 Sacrificing a pawn temporarily but Black swiftly regains it. 13 Bxe3 Bxe3 14 fxe3 fxg4 15 Ne4 Nf6 16 Bg2 0-0 17 c5 Kh8 18 0-0-0 Bf5 Short continues in buccaneering style. With the text move he clearly has a piece sacrifice in mind. Safer, though, is 18 … Qe7 19 d6 cxd6 20 cxd6 Qe6 when White’s passed d-pawn can be contained. 19 Ng3 Bg6 20 h5 (see diagram 2) 20 … Nxh5 The point of Black’s previous play. After the alternative of 20 … Bf7 White continues with 21 h6 when the prophylactic measure he introduced with his 11th move is suddenly converted into a weapon of attack undermining Black’s king’s flank. 21 Nxh5 Rf2 Black has offered a piece to stir up various threats. Sadly, the concept is not fully sound and Aronian now presses home his advantage by means of a careful consolidating network of defensive resources. 22 Bf1 Qf8 23 Ng3 Qxc5+ 24 Qc3 Qe7 25 e4 Qg5+ 26 Kb1 Qf4 27 Ka1 Rf8 28 Rg1 The only possible danger for White is that Black somehow energises his kingside pawns. However, Aronian’s careful play ensures that this never happens. 28 … Rf7 29 e3 Qg5 30 Bc4 Rd7 31 Qb4 b5 32 Nf5 This creates a mate threat on f8. 32 … h5 33 Qe1 Rf3 34 Be2 Rh3 35 Bf1 Bxf5 36 Bxh3 Bxe4 37 Bg2 Bxg2 38 Rxg2 h4 39 Qb4 Black resigns.