I did consider 5.f4. Hugh Myers mentioned it in the link, that's why I mentioned it in the PGN I attached. Didn't you already post this same game in a different Nimzowitsch thread?

I saw some analysis from Lorenzo Buttari 
http://bdgpages.blogspot.com/2009/01/gambitting-against-nimzovich-defense.html

1. e4 Nc6 2. d4 d5 3. Nc3 dxe4 4. d5 Ne5 5. f3 (This 5.f3 gambit is not convincing if black declines, but I have won a few games with it as white, so I was interested to follow the analysis when I came across it.) 5... exf3 6. Nxf3 Nxf3+ 7. Qxf3 Nf6 8. Bf4 Bg4 (instead of 8... a6) 9. Bb5+ c6 10. dxc6 Bxf3 11. c7+ (11. cxb7+ Nd7) 11... Qd7 12. Bxd7+ Nxd7 13. gxf3 e5 "the main question is if White's position is worth a pawn" (Hugh Myers).

Wait! Let's look deeper at that parenthetical variation:
Position after 11. cxb7+ Nd7.

12. gxf3 Rb8 13. Bxb8 Qxb8 14. O-O-O Qxb7 15. Rxd7 (The previous moves were by me, but 15. Rxd7 is by Stockfish, instead of my idea 15. Rd3) 15... Qxb5 16. Nxb5 Kxd7 17. Rd1+ Ke6 18. Nxa7. I call that +/-. Black might be able to draw, but it will not be easy. Later I might get interested in trying to prove a win for white, but that certainly belongs in the endgame sub-board.

Glenn Snow wrote on 10/17/11 at 05:04:29:


I've posted some long variations after this move and it was the most popular and quoted move that I'd seen, however it doesn't appear to be best.  If White instead plays 9.f3!, I now believe he has a comfortable advantage in all variations.  I was only able to find one game with this move where White only drew but he misplayed it fairly early on.  I'm now inclined to give 3...dxe4 the "?!" annotation and would strongly advise anyone wanting to venture this variation to play 3...e6.

I always play 3.--a6 and at this point, white thinks, that black is a stupid beginner.But after 4.exd5-Nb4 5.Nf3 (5.Bc4-Nf6)-Bf5 and white's position looks very bad after 6.Ld3-Bxd3 7.cxd3-Nxd5. Perhaps 4.a3 is an option, but then 4.--Nf6.
3.--Nf6 is an alternative

charlesgalofre wrote on 06/13/11 at 00:50:26:


I suppose I should have mentioned this when this was originally posted, but the title (subject) of the thread is 3...dxe4.  So anything else is off topic.  It's not that I think the move is necessarily the best but it might be and there's no doubt to it still be under-explored.  It has potential to be a real point scorer for someone willing to learn it.

Someone else mentioned that 2.Nf3 is now the main line.  That may be more common these days and is, in my opinion, the real reason why 1....Nc6 isn't more popular.  It's difficult to find a good reply that's also unique to the opening (of course Black could reply 2...e5).  Other threads on the forum cover some of the better tries.

Markovich wrote on 06/16/11 at 16:26:16:

Yes i 've found 9.Bb3! this morning too

charlesgalofre wrote on 06/13/11 at 00:50:26:


Jacob Aagaard had a splendid (informative and amusing) article on this line in SOS vol 11 (2009), concluding that Black is OK

charlesgalofre wrote on 06/13/11 at 00:50:26:


It's a very interesting variation and has been discussed on this forum before.  It still has high practical value but I believe it's been shown to be dubious against best play.