Other Tries
Outside of the Muzio, all these tries are considered suspect to varying degrees. I’ve seen a few comments about these on ChessPub but most work has gone into the Kieseritzky, Rosentreter, or Quaade. I’ll just give what I have in NCO and McDonald’s book. There’s a lot of transpositional possibilities between these, the Rosentreter, and the Pierce.

[1] Muzio Gambit (4 Bc4 g4 5 O-O) NCO gives 5…gxf3 6 Qxf3 Qf6 7 e5 Qxe5 8 Bxf7!? (8 d3 Bh6 9 Nc3 Ne7 10 Bd2 with comp.) 8…Kxf7 9 d4 Qxd4+ (9…Qf6 10 Bxf4 +/-) 10 Be3 Qf6 11 Bxf4 (Yoos-Kirton, Saskatoon 1994) with compensation. Michael Jensen claims 8 Bxf7 is bad (Fritz seems to agree, suggesting 11…Ne7 12 Nc3 Qc6 and 11…Nc6 12 Nc3 Bc5+). He and MNB recommend looking further at 7 d3, given by Bucker. The big problem with the Muzio is 4 Bc4 Bg7! and the Hanstein/Philidor complex.

[2] Allgaier Gambit (4 h4 g4 5 Ng5) NCO gives 5…h6 6 Nxf7 Kxf7 7 d4 f3! 8 Bc4+ d5 9 Bxd5 Kg7 10 gxf3 Nf6 11 Nc3 Bb4 -/+

[3] Ghulam-Kassim Gambit (4 Bc4 g4 5 d4) After 5…gxf3 6 Qxf3 d5! 7 Bxd5 Nf6 8 O-O c6! there is 9 Bxf7+ Kxf7 10 Qxf4 Bg7 11 e5 Rf8 12 exf6 Kg8! (Zak) and 9 Nc3 cxd5 10 exd5 Bg7 11 Bxf4 O-O 12 Bg5 Bg4! (Fritz improving on ECO) 13 Qf4 Nbd7 -/+

[4] McDonnell Gambit (4 Bc4 g4 5 Nc3) Now 5…gxf3 6 Qxf3 d5 7 Nxd5 Nc6 8 O-O Bd6 9 d4 Nxd4 10 Qh5 Be6 11 Bxf4 Bxf4 12 Nxf4 Nf3!! 13 Rxf3 Qd4+ 14 Kh1 Bxc4 15 c3 Qxe4 =+ (McDonald)

[5] Salvio Gambit (4 Bc4 g4 5 Ne5) McDonald gave 5…Qh4+ 6 Kf1 Nc6! 7 Nxf7 Bc5 8 Qe1 g3 9 Nxh8 Bf2 10 Qd1 Nf6 11 Be2 d6 12 c3 Bg4 13 h3 Ne5 14 d4 f3 15 Bxf3 Nxf3 16 gxf3 g2+ 17 Ke2 Bxf3+ (Goncarenko-Alekseev, Corr 1963) with 18 Kxf3 gxh1Q+ 19 Qxh1 Qxe4+ advantage to Black, but it seems play can be improved for both sides at times.

[6] Lolli Gambit (4 Bc4 g4 5 Bxf7+) has the distinction of being the line Neil McDonald was most pessimistic about in his already pessimistic (for White) KG book. He gives 5…Kxf7 6 Ne5+ Ke8 7 Qxg4 Nf6 8 Qxf4 d6 9 Nf3 Rg8 -/+

[7] Sorenson Gambit (4 d4 g4 5 Ne5) McDonald has some analysis on this (mostly quoting Zak, it seems), and it looks like White has a draw after 5…Qh4+ 6 g3 fxg3 7 Qxg4 f2+ 8 Qxh4 gxf1Q 9 Nc3. Charles Kennaugh comments “The main drawback to this line is that if black plays 7...g2+ 8.Qxh4 gxh1Q white only seems to have a draw which he should probably take immediately with 9.Nxf7 Kxf7 10.Qh5+ Kg7 11.Qg5+ etc. Black does himself no particular favours playing for a win with 9...Be7 10.Qh5 Qxe4+ 11.Kd1 Qxd4+ 12.Bd2 Qf6?! (12...Nf6?? 13.Nd6+ Kd8 14.Qe8+!; 12...Kf8! 13.Ne5 Qf2 14.Bh6+ Nxh6 15.Qxh6+ Ke8 16.Qh5+ Kf8=) 13.Nd6+! Kf8 14.Qe8+ Kg7 15.Bc3 Bxd6 16.Bc4.”

McDonald quotes ECO with 7…Qxg4! 8 Nxg4 d5 9 Ne3 dxe4 10 hxg3 Nc6 11 Bb5 Bd7 where White has some compensation (Black’s kingside structure) but not enough. (NCO agrees, giving the position =+) This line is pretty similar to the Quaade above, but inferior as the developed c3 knight is probably worth more than the move d2-d4.

Kennaugh gives 9.Ne5! f6 10.Bf4 Bg7 and now instead of the piece sacrifice 11.exd5?! dxe5 12.dxe5 Nd7 13.Bb5 a6 14.Bxd7+ Bxd7 which Glazkov gives as slightly better for black (though that assessment is untested) white can simply play 11.Nd3 with the idea 11...dxe4 12.Nc5 f5 13.Nc3! with a strong initiative for the sacrificed pawns.

References: McDonald, Bucker (esp for 7 d3 Muzio according to Jensen), NCO, Charles Kennaugh (link above) for the Sorenson Gambit.

Quaade Gambit (4 Nc3 g4 5 Ne5)

• [1] 5…Qh4+ 6 g3 fxg3 7 Qxg4 g2+? 8 Qxh4 gxh1Q 9 Qh5! +-
  
  • a) 9…Be7 and now Bird-Anon. 1886 features a nice smothered mate after 10 Nxf7 Nf6 11 Nd6+ Kd8 12 Qe2 Rxe8 13 Nf7#
  • b) 9…Nh6 10 d4 d6
    10…Bb4 11 Bxh6 Qxe4+ 12 Kd1 Qxd4+ 13 Ke2 wins; 10…d5 is similar to line given
    11 Bxh6 Be6
    11…dxe5 12 Qxe5+ Be6 13 Qxh8 is good for White
    12 O-O-O gives tremendous compensation for the exchange. (Analysis by Ben Hague)
• [2] 5…Qh4+ 6 g3 fxg3 7 Qxg4 Qxg4 8 Nxg4 d5 9 Ne3! (Craig Evan’s idea)
  
  • a) 9…d4 10 Nb5 Na6 11 Nxd4 (Evans-Canizares, IECC 2004) += or +/-
  • b) 9…c6 10 exd5 Nf6 11 hxg3
    Fritz likes 11 dxc6 Nxc6 12 Nb5
    11…Bd6 12 Ne2 Nxd5 13 b3
    13 d4 is better, keeping the queenside pawns together after knights are exchanged
    13…Nxe3 14 dxe3 = (Canizares-Evans, IECC 2004)
  • c) 9…dxe4 (Fritz’ favorite) 10 Ned5 Kd7 11 Nxe4 +=
• [3] 5…Nc6 (suggested by JEH) 6 Nxg4 Qh4+ 7 Nf2 Bc5 8 d4 Bxd4 9 Qf3 (Johansson: “looks roughly level at the first glance but there’s life in the position. After Qxf4 the queens may be coming off when pawns f7 and h7 may be weaker than the pawn e4 so Black may want to compensate by doubling the c-pawns with Bxc3 which in turn gives away the bishop pair.”)

Summary: Like the Rosentreter above, the Quaade is a move-order attempt to steer play into the modern Fischer Defense lines (3…d6 4 d4 g5 5 Nc3), but it also allows 4…g4. Unlike the Rosentreter, this line is not a knight sac as best is 5 Ne5!

Line [1] (5…Qh4+ with 7…g2+?) is clearly good for White; Line [2] (5…Qh4+ with 7…Qxg4) is also holding up well and should promise White at least an edge (even materialistic Fritz favors White in almost every line); Line [3] (5…Nc6!?) is probably Black’s best try, with rough equality but an interesting position (I’d prefer White).

The problem with the Quaade is not after 4…g4; rather 4…Nc6! transposing to either a Pierce Gambit (5 Bc4 g4 6 O-O) or Hamppe-Allgaier (5 h4 g4 6 Ng5!?).

References: Most analysis is homegrown here at ChessPub with Craig Evans responsible for the key idea (9 Ne3!). There’s a Quaade thread but most information is on a declined position also reached through the Fischer Defense – Furhoff Attack. Most info is hidden in the big threads (Death of KG, New Look at KG).

So last summer, I thought it'd be great to consolidate and summarize a lot of the homegrown KG analysis that can be found around these parts - ChessPub truly is a great resource for the KG even if no fully acceptable paths have been found (yet) after 3 Nf3.

After a little work, I got very ambitious and even suggested creating a playable e-book to hold all the analysis. I was going to try and merge analysis from just about every source I could get my hands on. Needless to say, that never ended up happening. BUT I do still have some of the material on the:

• Rosentreter (3 Nf3 g5 4 d4 g4 5 Bxf4!?)
• Quaade (3 Nf3 g5 4 Nc3 g4 5 Ne5!?)
• Furhoff Attack (3 Nf3 d6 4 d4 g5 5 Nc3 Bg7 g3) - a line in the Fischer Defense which I named after its strongest proponent
• Strongest lines for most of White's "misc" gambits after 3...g5 (excluding the Hanstein/Philador)
• A rough guide to forming a repertoire that involves any of the ...g5 lines
• A ...g5 systems transposition table
• General notes on naming convention, strategy, etc

While organizing some of my chess-related files, I found it this afternoon and figured I'd throw it up. There's nothing here that can't be found elsewhere on ChessPub, but it's a fairly nice compilation, if I do say so myself.

Long live the KG! (But it will have to be resuscitated by a stronger player than myself...)
David