Is the Ruy Lopez Siesta Variation Sound?

I've heard that some of the lines in the Modern Steinitz are unsound, and I was just wondering if this line is good for black. I haven't been able to find many recent GM games so I'm not sure if it was refuted or if it is simply out of style at that level right now.

Just did a very quick glance at some of this guys games. He has used it a couple handfuls of times.  http://www.365chess.com/search_result.php?search=1&m=10&n=17180&bid=9838

Things I have found out:

1.) His results are often not favorable.

2.) Whatever side black wants to castle on, his opponets tend to exploit either way. 

3.) f5, longterm gives whites pieces more activity. 

Thanks, very helpful info. Time to go searching for a different Spanish variation...

Somebody just uncorked the following apparent novelty on me on move 10 in a correspondence game on FICGS, it may just be the refutation:

Amazing that you are rated 2000 and don't know the answer

You must be joking. The Exchange variation is a perfectly acceptable alternative to 4. Ba4. However, after 4. Bxc6 dxc6, the move 5. Nxe5? is a mistake, since 5...Qd4! wins the pawn back.

Sriky:

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Bxc6 dxc6 5. Nxe5?! Qd4! 6. Ng4! Qxe4+ 7. Ne3 Bc5 and Black has regained the pawn and stands slightly better.

Ok so can we get back to the GD Siesta variation now?

Actually even the engine isn't complaining much after 14. Re3; the following is a dump of some Stockfish6 lines:

14.Re3 d4 15.Rh3 b5 16.Bc2

(16.Bc2 Stockfish 6 64 0.00 (depth 33)  Bc5 17.b4 Bb6 18.c4 d3 19.Rxd3 Bxf2+ 20.Kxf2 Ng4+ 21.Kg3 Qf6 22.Qxg4 Ne5 23.Rf3 Nxf3 24.gxf3 Qxa1 25.Qe6+ Kh8 26.Qe4 g6 27.Bb3 Kg7 28.cxb5 Qxc1 29.Qe7+ Kh6 30.Qh4+ Kg7 31.Qe7+)

(16.Bc2 0.00 (depth 33)  Bd6 17.b4 Qd7 18.Bb2 Rae8 19.Bb3+ Kh8 20.Nc2 Ng4 21.f3 Nge5 22.Qf1 Ng6 23.Nxd4 Nxd4 24.cxd4 Nf4 25.Rh4 Qf5 26.d5 Ng6 27.Rh3 Nf4 28.Rh4)

(16.Bc2 0.00 (depth 33)  Qd7 17.b4 Rae8 18.Bb2 Bd6 19.Bb3+ Kh8 20.Nc2 Ng4 21.f3 Nge5 22.Qf1 Ng6 23.Nxd4 Nxd4 24.cxd4 Nf4 25.Rh4 Qf5 26.d5 Ng6 27.Rh3 Nf4 28.Rh4)

(16.Bc2 0.16 (depth 32)  h6 17.Bb3+ Kh8 18.d3 Qd7 19.Nc2 Bc5 20.c4 Ng4 21.f3 Ne3 22.Qe2 Rae8 23.Bxe3 dxe3 24.cxb5 axb5 25.Rh5 Rf5 26.Rh4 Rd8 27.Rd1 Nd4 28.Nxd4 Bxd4 29.Re4 Rf6 30.f4 c5 31.Re1 Rdf8)

Usually I let Stockfish go to about depth 40 before moving but there with so many equalizing lines I felt comfortable going ahead with 14...d4 and my opponent responded 15. Re1?! and Black may get the upper hand with 15...b5, especially after 16.Bb3+ Kh8 17.Nc2 and now more than likely 17...d3

More testing is probably 14. Bc2 as in the ICC game you quote but Black may be able to improve with 14...Qd7 (as opposed to 14...Bxa3 15.bxa3 Qd6), or 14...Bc5

The following was quite a bloodbath for White.  Despite that it would lose a tempo he needed to play 15.Rh3 instead of 15. Re1?

Here's a dump of some Komodo analysis at the final position:

(24...Nf6 Komodo 9.2 64-bit  -3.39 (depth 27)  25.Qf2 Qxf2+ 26.Rxf2 Nxd5 27.axb5 axb5 28.b3 Kg8 29.Ba3 Rf5 30.Bc5 Nd7 31.Ba7 Nf4 32.h3 Nc5 33.b4 Na4 34.Rb1 Nb6 35.Bxb6 cxb6 36.Kh2 Re2 37.Rbf1 Rfe5 38.Kg3 g5 39.h4 Rxf2 40.Rxf2 Re2 41.Rxe2)

(24...Nf6 -3.80 (depth 27)  25.Bb7 Ng6 26.Qf2 Qh6 27.Re1 Nf4 28.Rxe8 Rxe8 29.axb5 Qg5 30.Kf1 Qxb5 31.Qd4 Qxb7 32.Qxf4 Qb3 33.Qa4 Qe6 34.Qd1 Qd6 35.g3 Re2 36.Qxe2 dxe2+ 37.Kxe2 Qb6 38.Kf1 Qb5+ 39.Kf2 Kg8 40.Ra3 Qd3 41.Ra1)

(24...Nf6 -4.14 (depth 27)  25.Qd4 Qh6 26.Be4 Nfg4 27.fxg4 Rxf1+ 28.Kxf1 Nxg4 29.Bxd3 Qh4 30.Be2 Re4 31.g3 Qh3+ 32.Ke1 Rxd4 33.cxd4 Qxh2 34.Kd1 Nf2+ 35.Kc2 Qg2 36.Ra3 Qe4+ 37.Bd3 Nxd3 38.Rxd3 bxa4 39.d5 Kg8 40.Kc3 Qe5+ 41.Kc2)

(24...Nf6 -4.67 (depth 27)  25.axb5 Nxd5 26.Qf2 Qh5 27.Kh1 Nf4 28.b3 axb5 29.Ba3 Rf6 30.Bc5 Ne2 31.Be3 Qf7 32.Qh4 Rf5 33.Qb4 Rh5 34.h3 Ng3+ 35.Kg1 Nc6 36.Qg4 Nxf1 37.Rxf1 Rf5 38.b4 Rf6 39.Kh1 Qd5 40.Ra1 Ne5 41.Qh5)

Before moving? Are you allowed to use stockfish during your game?

6.d4 and white can force either a much better position or a forced draw. 6..fxe4 is the only move that doesn't go into a worse position. 7.Nxe5 dxe5 8.Qh5+ Ke7 9.Bxc6+ bxc6 10.Qg5+...now what?

On FICGS which is where these games are being played, yes.

If all White can do is force a draw against the Siesta, than 5...f5 would be the refutation of 5.c3 -- the onus is on White to find winning chances, whereas Black should be happy with equality.

A very common line in the Siesta Variation seems to be the Kopayev Variation: 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 d6 5. c3 f5 6. exf5 Bxf5 7. 0-0 Bd3. A line in the Kopayev that hasn't been mentioned on this thread, for whatever reason, I am not sure, but which seems good for white is 8. Qb3 (instead of the much more common - it would seem - 8. Re1):

First off, 8...Bxf1? is just a mistake after 9. Qxb7 Bb5 10. Bxb5 axb5 11. Qxc6+ when white will have the upper hand. 

position after 11. Qxc6+ 

If black tries the move 8...b5, it is met by 9. Qd5, attacking black's bishop on d3, and the hanging knight on c6, when black has nothing better than 9...Bf5 10. Qxc6+ Bd7 11. Qe4 Nf6 (better than 11...bxa4) 12. Qe2 bxa4 13. d4 e4 14. c4 (the black pawn on d4 is in an absolute pin...) Be7 15. Nfd2 with a bit of an advantage for white, even after 15...Bg4, 15...0-0, or 15...Rb8.

So black should probably go with the move 8...Ne7 - however, white has a nice continuation in 9. Ng5 when black has to be very careful.  What is the best move for black?  9...Qc8 is best. Other moves will lose for black quickly. 10. Qf7+ Kd8 11. Bd1 Bg6 12. Bh5 and now again, black has to be very careful, as 12...Bxf7 doesn't cut the mustard after 13. Nxf7+ Kd7 14. Bg4+ (haha, black, you goofed-up!) Ke8 15. Bxc8 Kxf7 16. Bxb7 Ra7 17. Bxa6 with a nice lead for white. So black must respond instead with 12...Bxh5 or 12...Qd7: 12...Bxh5 13. Qxh5 g6 14. Qd1 Qf5 15. d4 exd4 16. cxd4 h6 17. Nf3 with a slight edge for white; 12...Qd7 13. Bxg6 Nxg6 14. d4 exd4 15. cxd4 Kc8 (not 15...Nxd4? 16. Qc4!) and white has better central control and greater potential.

So, it seems to me, that this is a line of major importance in the Siesta Variation, that is not getting discussed. Furthermore, it seems that black has to play with great accuracy and even then, doesn't seem to get a lot out of the position in most lines of this.

Can some of the stronger players give feedback on what they think of 8. Qb3! (I give it an exclamation point for now!)?

True, but this post is on the Siesta Variation, not the Schliemann...

Thx for posting the Yandemirov game; this Yandemirov dude seems to know his stuff, as do you - very insightful and instructive! 
Hmmm, now why in the heck would they call this "Siesta"??  Seems like you'd not want to take one, right?? I guess black just yawning away, knowing he will win pretty easily whatever white throws his way...