Variation in Max Lange Attack In the position at 15:29 of this video, what are some possible variations the line starting with the move 12...Qe5 that lead to an advantage for white?

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 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. d4 exd4 5. O-O Nf6 6. e5 d5 7. exf6 dxc4 8. Re1+ Be6 9. Ng5 Qd5 10. Nc3 Qf5 11. Nce4 O-O-O 12. g4 Qe5
In that position, 12...Qe5 is the main line since the other lines all lead to clear advantages for white. 12...Qd5 and 12...Qg6 are forced losses in short order, while 12...Qg4, even though not best, it leads to crazy lines, which I also added to the analysis. Even then, there are a thousand more lines, but I added in only some of the most reasonable alternatives. If you wonder about about a line that was not included in a tactical sequence of captures, there is probably some obvious win that you should be able to find with a little thought.

After 12...Qe5, there are only two decent moves for white, which both lead to roughly equal games, but it is still incredibly complicated: 13.Nxe6, which is the main move, and even 13.fxg7 is not bad.

I used both my database, and what it shows has been played before, and a fairly strong computer running Stockfish 11 to come up with these lines. There is A LOT of stuff here, and I do not recommend trying to memorize all of it if that is your goal, but you can play through it and just enjoy some of the tactics.

In super tactical lines like this, especially as you get stronger, many players memorize a few of the main branches of such lines, but they know that if the opponent varies from them, that there is something there, and spend more time to try to find it over-the-board. In other words, the opponent not playing the memorized line is like a big flag waving that there is something hidden there, and you have to find it.

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 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. d4 exd4 5. O-O Nf6 6. e5 d5 7. exf6 dxc4 8. Re1+ Be6 9. Ng5 Qd5 10. Nc3 Qf5 11. Nce4 O-O-O 12. g4 Qe5 {This is the main move because the other two are bad to just losing in a few moves.} (12... Qd5 $4 13. fxg7 Rhg8 14. Nf6 Qd6 15. Nge4 Qe5 16. f4 d3+ 17. Kg2 Qd4 18. c3 $18 {And the queen is trapped. This has been played three times in my database.}) (12... Qxg4+ $2 13. Qxg4 Bxg4 14. Nxf7 gxf6 $1 (14... Bd6 15. Nxd8 Rxd8 16. Nxd6+ cxd6 (16... Rxd6 $4 17. Re8+ Kd7 18. fxg7 $18) 17. fxg7 $16) 15. Nxh8 Bb4 (15... Rxh8 16. Nxc5 Nb4 17. f3 Bf5 18. c3 Nc2 19. Bf4 Nxa1 20. Rxa1 dxc3 21. bxc3 $18) (15... Bh3 16. Nf7 Rg8+ 17. Ng3 Bb4 18. Re4 Bf5 19. Re2 d3 20. Re3 Bg6 (20... d2 21. Bxd2 Bxd2 22. Nh6 $18) 21. c3 Bc5 22. Nh6 Rd8 23. Nf1 Bxe3 24. Bxe3 $16) 16. c3 dxc3 17. bxc3 Nd4 (17... Ne5 18. Bf4 Nf3+ 19. Kg2 Nxe1+ 20. Rxe1 Be7 21. Ng3 Ba3 22. f3 Bd7 23. Nf7 Re8 24. Rd1 $16) 18. Bf4 f5 (18...Nf3+ 19. Kg2 Nxe1+ 20. Rxe1 Be7 21. Ng3 Ba3 {As above.}) 19. cxb4 Nf3+ 20. Kf1 Nxe1 (20... fxe4 21. Rxe4 Bf5 (21... Rxh8 22. Rxc4 c6 $18) 22. Nf7 Bxe4 (22...Rg8 23. Nd6+ $3 {Only move.} cxd6 (23... Kd7 $4 24. Nxf5 Rg1+ 25. Ke2 Rxa1 26. Kxf3 $18) 24. Rxc4+ Kd7 25. Rd1 $18) 23. Nxd8 Kxd8 24. Ke2 $16) 21. Nf7 Nd3 (21... Nc2 22. Rc1 Rf8 $4 23. Ned6+ cxd6 24. Nxd6+ Kd7 25. Rxc2) 22. Nxd8 Nxf4 (22... fxe4 23. Bg5 h6 24. Bf6 c3 25. Bxc3 Kxd8 26. Kg2 $18) 23. Nxb7 Kxb7 24. Nc3 $16) (12... Qg6 $4 13. Nxe6 fxe6 14. fxg7 $18 {As both Bc5 and Rh8 hang.}) 13. Nxe6 fxe6 (13... Qxe6 $4 14. Nxc5 $16) 14. fxg7 Rhg8 15. Bh6 {It is important to prevent that rook from becoming active against your king.} d3 (15... Be7 {Keeping an extra piece on g5, which may be relevant later. It also stops Nxc5.} 16. Qf3 Qd5 (16... d3 17. c3) 17. Qf7 $1 $16 {Stopping Ne5 with Rad1 next.}) 16. c3 d2 {This is the main line, but there may be room for improvement here.} 17. Re2 Rd3 18. Qf1 Qd5 19. Nxd2 {This natural computer move is new, and should leave black looking for improvements on move 16.} (19. Rd1 {This is the line that was played previously.} Ne5 20. Nf6 Qf3 21. Nxg8 Qxg4+ 22. Kh1 Qf3+ 23. Kg1 {Withe perpetual check.}) 19... e5 (19... Ne5 $2 20. Rxe5 Qxe5 21. Nxc4 Qe4 22. Ne5 $1 $18) 20. Ne4 Qe6 21. g5 $16 Qg4+ 22. Ng3 $18