I know I still have a loose end in the blog to close -- the King's Bishop Gambit main line, 5.Nf3 with my preferred reply of 5...Qh6 (instead of book 5...Qh5). As per my Chess Theory post, it too leads to a virtually equal position with best play.
Which leads me to the topic of this post, another draw-by-repetition end to a theoretical opening line. I was interested to see GM Andy Soltis's article in the August 2012 Chess Life (http://main.uschess.org/content/view/11830/661) on that very topic (pp. 12-13). (Was he one of the 2 pageviewers of my Chess Theory post? :-) ) Andy points out main-line draws-by-repetition for Najdorf Poisoned Pawn Accepted, Muzio Gambit Accepted, Rice Gambit, Belgrade Gambit, Richter-Rauzer 7.Be3, a Queen's Gambit declined line, and a couple of Modern Defense lines.
And I believe I have found another draw-by-repetition with best play, in the Fried Liver:
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Nxd5 6.Nxf7 Kxf7 7.Qf3+ Ke6 8.Nc3 Ncb4 9.a3 Nxc2+ 10.Kd1 Nxa1
I call this the Full Fried Liver, as opposed to 10...Nd4 (the Weak Fried Liver?) which also seems to be a dead-even game in the proposed main line 11.Bxd5+ Kd6 12.Qf7 Qe7 13.Ne4+ Kd7 14.Nc5+ Kd6 15.Nxb7+ Bxb7 16.Qxe7+ Bxe7 17.Bxb7 Raf8 18.Rf1.
Perhaps surprisingly, the popular line 11...Kd6 loses here to 12.d4: 11...Kd6 12.d4 c6 13.Bf4! exf4 14.Qxf4+ Kd7 15.Re1 and it's mate in 7 due to the Qf5+ threat (15...cxd5?? 16.Bb5#). I recently won an over-the-board game in this line after 12...Kd7? 13.Re1 Qh4? 14.Qf5+ Kc6 15.Qxe5 Bd6 (protecting against 16.Qxc7#, but:) 16.Bb5+ Kxb5 17.Nc3+ Kc4 18.Qd5+ Kd3 19.Re3#.
Black's only reasonable try after 11...Kd6 12.d4 seems to be 12...Be6 but it also seems to lose, to 13.Re1 b5 14.Nb4 bxc4 15.Qc6+ Ke7 16.Bg5+ Kf7 17.Bxd8 Rxd8 18.Qxc7 Rd7 19.Qxe5. (Or 13...c6 is even worse: 14.Rxe5 Bxd5 15.Rxd5+ cxd5 16.Qxd5+ Kc7 17.Bf4+.)
Update. There are improvements on both sides leading to a different main line after 11...Kd6 12.d4 Be6 13.Re1. After 13...b5 14.Nb4, 14...Bxc4! is a big improvement for Black because it allows 15.Qc6+ Ke7 16.Bg5+ Kf7 17.Bxd8 Rxd8 18.Qxc7 Be7!, and then also 19.Nc6 Rxd4+ 20.Nxd4 Rd8 21.Qxe5 Bf6! with minimal White advantage. But White has an even bigger improvement in 11...Kd6 12.d4 Be6 13.Re1 b5 14.Rxe5!, when 14...bxc4 15.Nf4 is decisive for White due to the control of e6.
So 13...b5 is busted for Black. The main line seems to be instead 13...h5 (threatening a royal skewer (ok actually a royal pin, but skewer sounds better)) 14.Qe4 and White cleans up on the e file: 14...Kd7 Qxe5 15...Bg4+ 16.f3 Bd6 17.Qxg7+ Kc6 18.fxg4 b5 19.Bd3 with threat Be4.
12.Nc7+ Kd6 13.Nxa8 Qh4 14.Qd3+ Qd4 15.Qxd4+ exd4 16.d3 Bf5 17.Re1 Kd7 18.Re5 g6 19.Ra5 a6 20.Nb6+ Kc7 21.Na8+ Kd7 draw.
If anyone thinks they have an improvement for either side, please post a comment. Thanks.