Paddy wrote on 01/09/21 at 21:16:01:
[quote author=262E2E24170 link=1589129926/3#3 date=1589380593]Mostly my opponents play ...g5 lines and I get good results with Quaade-type lines.
As so often I think Black's attempts to squeeze all fun out of a gambit even more worriesome than attempts to refute it. Unfortunately 4.Nc3 Nc6 5.g3 d6 6.d4 Nc6 7.d5 Ne5 shows that White's 5th was not exactly optimal. If weaker opponents will play this against you in the near future you can blame me, Paddy.

GM Wahls wants to refute the KG and that's something I applaud, because it invariably means chances for the gambiteer. Here I have some suggestions. I haven't put much effort in them as 5...d6 above has discouraged me; plus I prefer to waste my time on the Classical Dutch today.
GM Wahls' first video gives 1.e4 e5 2.f4 exf4 3.Nf3 Nf6 4.e5 (indeed, if White's to play 4.Nc3 it's time to look for greener grass) Nh5 5.Be2 g5 6.O-O Ng7 7.d4 h6 and hang on, this looks like a Hanstein with the knight on g7 iso g8 plus some extra moves for White, some useful, some not (particularly e5 and Be2). So yes, 8.g3 d5 9.exd6 Bxd6 and now I suggest 10.Ne5 gxh2+ 11.Kh1 Be6 12.d5 Bxd6 13.dxe6 Bxe5 14.exf7+ Ke7. Before trying this in a corr. game I'd spend some hours analyzing this and then some more, but the practical chances are obvious with that centralized king.
Another idea is 8.Qe1 eg Be7 9.Bd3 d5 10.exd6 Qxd6 11.Nc3 but at the moment I don't see what to do after O-O.
Ninally I offer 8.Bc4 d5 9.exd6 Bxd6 10.Re1+.Be7 11.b3.
Possibly 8.Re1 Be7 from Buschbaum-Cossmann, corr 2014 is also worth looking at; not 9.Nc3 as in the game, but 9.c4 d6 10.cxd6 cxd6 11.Nc3 O-O 12.Nd5.though in such positions I always worry about White's queen's bishop and square e3.
While looking at GM Wahl's second article I found this game:
Corbat,P (2419) - Sueess,F (2245)
SUI/C26/F (SUI) ICCF, 20.10.2017
1.e4 e5 2.f4 exf4 3.Nf3 Nf6 4.e5 Nh5 5.Be2 g5 6.0-0 h6 7.d4 Ng7 8.g3 fxg3 9.Bc4 d5 10.exd6 Bxd6 11.Nxg5 hxg5 12.Bxf7+ Kf8 13.Bg6+ Kg8 14.Bf7+ Kf8 15.Bg6+ Kg8 16.Bf7+ ˝-˝
But yeah, 7...d6 is superior - and the moment I can't find anything better than 8.Re1 Be7 9.exd6 cxd6 10.Nc3. Getting the pawn back with Nxg5, opening the h-file, looks risky. Still at some point White hasn't any other option left. Finding the optimal circumstances is something I'll leave to someone else.
Re the Quaade, I agree that 1 e4 e5 2 f4 exf4 3 Nf3 g5 4 Nc3 5.g3 d6 6.d4 Bg7 is one of the most challenging move orders and that 7 d5 Ne5 8 gxf4 gxf4 9 Bxf4 Bg4 10 Bb5+ Kf8! 11 Be2 doesn't seem promising for White, especially after 11..Nxf3+ 12 Bxf3 Bxc3+!? 13 bxc3 Qf6 when White's slight lead in develpment after 14 0-0 Qf4 15 Bxg4 seems inadequate compensation for his bad structure and exposed king.
A better practical try might be 7 Bb5!? a6! 8 Bxc6+ bxc6 and now the engine suggestion of 9 h3!?, when, simply in search of practical chances I've looked at 9... h5 10. gxf4 g4 11. hxg4 hxg4 12. Rxh8 Bxh8 13. Ng5 f6 14. Nh3 Ne7 (14... gxh3 15. Qh5+) 15. Nf2 f5 16. Be3
and 9...g4 10. hxg4 fxg3 (10... Bxg4 11. Bxf4) 11. Bg5 Bf6 12. Bf4 Bxg4 13. Bxg3 h5 14. Qd3 h4 15. Bh2
Bxf3 16. Qxf3 Bxd4 17. e5 dxe5 18. Ne4 Bxb2 19. Rd1 Qe7 20. O-O Rh6 21. c3 Rg6+ 22. Kh1 Rd8 23. Rde1. Crazy stuff.
Thanks for the Schallop suggestions, which I'll certainly study.