patzer2: Here's a look at the Satuday puzzle (15. ?) and game with the chessgames.com opening explorer (OE), Deep Fritz 15 and Stockfish 8:<1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6> This is by far the most popular move in this opening line of the Sicilian. It had its debut with Kupchik vs Santasiere, 1926.
<6. Be3> This enters the Najdorf (B90) Sicilian as in Black's win in Rossolimo vs Fischer, 1966.
<7... e6> This is Black's second most popular move. More often played is 6...e5 as in White's win in Shirov vs N Delgado Ramirez, 2017 or Black's win in
A Meijere vs G Mammadzada, 2017.
<7. g4> This early aggressive White move was first played without success, with Black winning in Lombardy vs Gligoric, 1961.
After this inauspicious beginning, it was nearly two decades later before White ventured 7. g4 again, with a White win in B Perenyi vs A Schneider, 1978.
White's win a year later in Kasparov vs Polugaevsky, 1979 no doubt hepled popularize 7. g4.
Though 7. g4 is still frequently played, it's not the most popular.
The second most popular move and the computer preference is 7. Be2 as in the draw in D Swiercz vs S Shankland, 2017.
The most popular move is 7. f3, entering the B80 Sicilian Scheveningen, as in White's win in Robson vs Y Zherebukh, 2017.
<7...e5> This is the computer choice and a current popular try, but most often played is 7... h6 as in Black's win in Yifan Hou vs Van Wely, 2016.
<8. Nf5> Of 145 games in the OE in this line, 8. Nf5 has been White's only choice. Though it might have surprise value in skittles or blitz, the alternative 8. Nb3!? Nxg4 9. Bd2 Nf6 10. Rg1 Be6 
to = leaves Black a pawn up with a solid position.
<8... g6 9. g5 gxf5 10. exf5 d5> The moves 8...g6 9. g5 gxf5 10. exf5 d5 are the most popular and theoretical best moves.
<11. gxf6> This is the second most popular try.
Slightly more popular and the computer preference is 11. Qf3 as in Black's win in N Matinian vs Navara, 2013.
<11... d4 12. Bc4 Qc7 13. Qd3 b5>
Though it's not a bad move, this is the only game with 13...b5 in the OE.
More often played is 13...dxe3 as in the draw in Lu Shanglei vs Yinglun Xu, 2016.
<14. Bd5 Bb7?> This is Black's decisive mistake.
Instead, Black can fight on with drawing chances after 14...Nc6 15. Bxd4 exd4 16. Qe4+ Kd7 17. 0-0-0 Bb7 18. Bxf7 Kc8 19. Be6+ Kb8 20. Nd5 Qe5 
(+0.45 @ 31 depth, Stockfish 8.)
<15. Bxd4!> 
(+2.24 @ 30 depth, Stockfish 8) With this strong move, which solves the Saturday May 13, 2017 chessgames.com puzzle, White is winning.
<15...Nd7> According to the computers, this move puts up the most resistance.
<16. O-O-O Bxd5?> By allowing17. Nxd5 (+7.74 @ 31 depth, Stockfish 8,) this makes it easy for White.
Putting up more resistance is 16... O-O-O, but White is still winning after 17. Be3 Bb4 18. Bxb7+ Qxb7 19. Nd5 Nc5 20. Bxc5 Bxc5 21. Rhe1 Rhe8 22. f4 e4 23. Rxe4 (+2.64 @ 33 depth, Stockfish 8.)
<17. Nxd5> (+7.74 @ 31 depth, Stockfish 8) White's advantage
is now clearly decisive.
<17...Qd6 18. Bxe5 Nxe5 19. Qe4 O-O-O 20. Nb6+ 1-0>
Kibitzing
sac: 18.Bxe5
