MNb wrote on 05/19/09 at 03:39:39:
I have never looked at 5.Qf3 ideas, so I can't help you here. After 4...d6 I would play 5.f4 as White, entering the KGD, which think somewhat better for White (my compatriot Willempie disagrees, but he refuses to buy stuff like the Fascinating King's Gambit). I did not like 4...0-0 too much because of 5.Bg5. Again this idea is known with colours reversed from the Italian, where Black only plays ...Bg4 after White has castled.
I have just consulted my notes on the Bishop's Game with 3...Bc5 4.Nc3 c6. Stubborn guy as I am I have tried a few years ago to make this work for White as well. My main line runs 5.Nf3 (5.Qf3 b5 6.Bb3 a5 7.a3 d6) d6 (d5 6.exd5 cxd5 7.Bb3 as 7.Bb5+ Bd7 is equal - compare Giuoco Piano) 6.a3 0-0 7.Ba2 Nbd7 (Bg4 8.h3 Bh5 9.g4) 8.0-0 Bb6 (Re8?! 9.Ng5! and White will get f2-f4 in) 9.Kh1 h6 (Re8 10.Ng5 Re7 11.f4) and here I could not decide between 10.h3, 10.Ne2 and 10.Nh4. Of course everything is "stolen" from the Giuoco Pianissimo.
Hope this helps a bit.
I appreciate the addition!
5. f4 is certainly another good option after 4...d6 (although the case is pretty good for 5. Qf3, too).
Worthy of note is that 5. Bg5 is actually more popular in practice after 4...c6 than 5. Qf3 (45 games for the former, 24 for the latter). The prodigy Hou Yifan even put it to use fairly recently when given the chance. It's probably more flexible, reserving the possibility of Qf3 in the future, or switching to earlier Nge2 structures.
Admittedly, however, I like the position after 5. Qf3 b5 6. Bb3 a5 7. a3 d6 for white more than the analagous lines with 5. Nf3.
5. Qf3 h6 (to prevent 6. Bg5) 6. Qg3!? (Hunkel - Davarnia, Neumuenster, 2000)
5...d6 6. Bg5 Nbd7 7. Nge2 b5 8. Bb3 a5 9. a4 b4 10. Nd1 (Timofeev - Provotorov, Kaluga 1997)
5...0-0 6. Bg5 transposes to 5. Bg5 below.
Anyway, some possible lines after 5. Bg5:
5. Bg5 h6 6. Bh4 d6 7. Nge2 Nbd7 8. 0-0 (Yifan - Zhukova, Ekaterinbrg, 2006)
6...0-0 7. Qf3 (Hadzh - Koslovskaya, Kiev, 2002)
5...0-0 6. Qf3 Be7!? (Ibragimov - Altounian, San Diego, 2004)
I'm liking white's possibilities a lot more with these Qf3/Bg5 ideas. I'm starting to think black should just stick to the ol' reliable 3...c6, Two Knights Defense variations, or the Closed Italian Game. I don't think allowing these ideas makes it easier for black to equalize.