backrank: Sadly, it is true that Mayet's resignation after 18. ... f4 is premature. Certainly the line given above by <keypusher> after 19. exf4 is correct. However, White can better play 19. g5 (!), which does not allow for an easy win for Black. Best line (after 19. g5) seems to be 19. ... d7 (slightly better than the immediate d3+) 20. d1 (20. xc5 d3+ 21. b3 b8+ 22. a2 c4+) d3+ 21. xd3 (21. b3 a4+!, 21. d2 e2+!) xd3+ 22. b3 b8+ 23. a2 (a4 d7+) c4+ 24. b1 d3 ( xc3) 25. c2 xa3 26. bxa3 (xa3 b4+) e1+ 27. d2 d3+ 28. xe1 xc3+, winning the exchange (analysis done with the help of Rybka).

However, I doubt that Mayet would have found 19. Qg5 (!). The many threats he had to face were simple too much for him, and he resigned.

18. ... xf2, instead of f4, would have given Black a simple win (or, alternatively, xf2 already on move 16). However, Anderssen always wanted to play brilliantly, maintaining the attack, and so he despised such trivial winning continuations :)

In summary, in spite of all the mistakes on both sides, the game is highly instructive in that White is punished for neglecting the development of his pieces and losing time in the opening. Anderssen sacrifices the exchange in order to prevent White from castling and to be able to attack the white king with the aid of a stunning knight manoevre (Nf6-d7-e5-d3!).

offramp:

click for larger view

19.Qg5 looks like a better defence. Black still has a very menacing position but I cannot see a killer continuation. I would imagine that Anderssen would have started off with 19...Bd3+ but if Mayet had then dared to play 20.Kd1! our Adolf might have had to settle for a draw.