FreeRepublic wrote on 05/19/18 at 00:41:04:
You provided the Scotch move order. White can also go for the Italian move order.
If White is going for the d2-d4 variations against both the Italian (Giuoco Piano) and the Two Knights then the Scottsih move order 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 is more precise. Black is almost forced to take on d4. That's not the case after 3.Bc4 Be7 4.d4 d6 5.Nc3 Nf6. Compare Tal-Filip, Astalos Mem 1963. White won (the line is easier for White anyway) but still it's nice to play Bf4 in one go instead of Tal's 9.Be3 and 11.Bf4.
The downside of the Scottish Gambit of course is making it impossible to play the Evans Gambit and 4.Ng5 against the Two Knights.
FreeRepublic wrote on 05/19/18 at 00:41:04:
As far as I can tell, white can also play: A) 1e4 e5 2d4 exd 3Nf3,
Yes, but 3...Bb4+ is stronger now as 4.c3 (4.Bd2 is not to be feared) dxc3 5.Nxc3 Nc6 6.Nf3 forces a transposition to the main line of the Göring Gambit.
FreeRepublic wrote on 05/19/18 at 00:41:04:
B) 1e4 e5 2Bc4 Nf6 3d4 exd 4Nf3,
Yes, but there are 2...Nc6 and 2...Bc5 to deal with. Also 1.e4 e5 2.Bc4 Nf6 3.d4 exd4 4.Nf3 Bb4+ 5.c3 dxc3 might be even stronger than similar lines.
2...Nc6 3.Nf3 Be7 (the Hungarian) forces slow positional play, exploiting a small advantage. That's objectively good, but not the type of play White is aiming for when playing the Scottish Gambit.
FreeRepublic wrote on 05/19/18 at 00:41:04:
and perhaps C) 1e4 e5 2d4 exd 3Bc4.
Again there is 3...Bb4+.
FreeRepublic wrote on 05/19/18 at 00:41:04:
Every sequence allows alternatives for each side.
And they might be more difficult to tackle.
FreeRepublic wrote on 05/19/18 at 00:41:04:
These additional lines have the merit of avoiding many lines of the Petroff.
Given my lifelong dislike of the Petroff this is an important argument. I'd say White's best bet is 1.e4 e5 2.d4 exd4 3.Nf3 as Nf6 4.e5 Ne4 5.Qxd4 d5 6.exd6 Nxd6 7.Bf3 Nc6 8.Qd2 is an attractive and easy way to play. Not all lines of the Petroff are to be avoided and 1.e4 e5 2.Nf3 Nf6 3.d4 exd4?! is one of them.