Is the Ruy Lopez Siesta Variation Sound?

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

Black plays the Schliemann to draw, and the Siesta to win.

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...

Valeri's opening repertoire is rather narrow, but he knows it by heart.

The firest instance of 9...Nd4! was in a game Minev-Damjanovic, Bad Liebenstein 1963, which was identical up to move 14. It's safe to assume that Valeri knew the game.

I have played him once as Black, and managed to draw from a worse position. He probably underestimated my blitzing abilities- I was in serious time pressure, as usual.

Stockfish, you lose...

Oh wait, no Stockfish does give the 9...Nd4 line, just didn't let it think long enough is all... But it still likes 9...Bf5 more... 

If this ever comes up in a game, now I'll try the 9...Nd4 line if I'm black.

Schliemann is draw at master level. Below, I like my chances.

Below where?  I cannot see the diagram....

Now, without further ado, it's time for my Siesta... I'm starting to see black very clearly now...

Yes it is soubd

sound

Below master level. I studied it for months, then after all of the boring scotches and italians,  I switched to sicilian.

Why can't white just move the rook?

Because T-Rex will eat it if he does! A good rook sandwich, so delicsh...
When the mice are away, the cat will play, and T-Rex is one big kitty.

But, seriously, I was wondering about the line: 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 d6 5. 0-0 can you still play 5...f5? That looks quite different, maybe terrible for black after 6. d4, so you only want to play f5 if white plays 5. c3, it sure looks like.

And for those who don't know T-Rex, he is my pet dinosaur, who lives in the phone book. Long story.

Yeah, you too?

  Wow, mi gatito habla española!  No Spanish torture for kitty-cat.  My kitty-cat doesn't always drink Dos Equis beer when he plays the Siesta, but whenever he does, it's lights-out...

A few interesting things I'm noticing here: White seems better with 5. 0-0 rather than 5. c3. Also, Lacina played 16. Qf1, but 16. Na3 would have been more in a fighting spirit. Then, maybe white can get a draw out of the thing. With the passive 16. Qf1 white has kind of sealed the coffin for himself. By move 19, white's position stinks; he really has no good moves to play... Seems to me anyway... Finally, white can try the interesting line 12. Ng5 (which is move 5 on the diagram below), instead of 12. Bb3 or 12. Kxf1, but 12. Ng5 doesn't quite work, I'm realizing, as black can play 12...Bxg2 13. Kxg2 bxa4 and 14. Nf7 Qc8 15. Qxc8+ Rxc8 16. Nxh8 exd4 17. d3 g6 18. Na3 Bg7 19. Bg5 Nc6 20. Re1+, but now black just plays 20...Kf8 21. Nxg6+ hxg6 22. Nc2 Rb8 and has the edge:

Black is ahead positionally...

Taylor has a 40 pg. chapter on the Siesta in his 2011 book "Slay the Spanish" which covers the Modern Steinitz in general, which is useful because White obviously has responses other than 5.c3.

One thing though, you must read the book critically.  For instance regarding the Siesta he leaves out a couple of playable moves in one variation, instead dismissing it on the grounds of one bad move.

Sorry to resurrect but black also has the possibility of making the modern Steinitz quite an aggressive Ruy response pairing the siesta with 5.0-0 Bg4 6.h3 h5 stuff. Do you guys feel that that option is sound and is a viable long term repertoire choice?

On the variation shown above in post 4, it is reasonable to think that black is fine even though a pawn behind. White has development issues with the knight on h3 and the queen's bishop stuck temporarily so that the rook is also not getting out easily. In contrast black has done all the basic development already with active knights. I think the computer analysis that follows shows this also.