fjd wrote on 12/15/17 at 21:47:23:
Slightly off-topic, but how is the 11...Nd7 line doing nowadays? I have good memories playing this line when I was younger, before switching to the Marshall. I remember it being considered nearly refuted a few times. Is Black meant to be okay?
I download games from The Week In Chess. From 2012 to 2016, white scores only 51% after 11...Nd7. I think theory is also positive on the Keres line. If you are just catching up, like me, the surprise is that after 12Nbd2 black prefers exd to the earlier cxd. The idea is to go into a Benoni type structure after 12Nbd2 exd 13 cxd Nc6 14d5 Nce5. At a glance it may not look like much. However black has some interesting resources on the king side. After 15Nxe5 Nxe5 16f4 Ng6 17Nf3, black can consider 17...Bh4 or 17...f5.
I prefer the Open to the Closed Ruy Lopez, but dabble in the Closed from time to time. I think black should always consider d5 by white. I suppose it could be labelled the "ultra-closed" variation. How does black best arrange his pieces after white separates black's king side from his queen side?
ChessPublishing has provided a variety of opinions on 12 d5. These are from various annotated games, and, possibly commentators:
"I continue to think that this move is excellent and leaves the Keres Variation under a cloud."
"This looks premature as Black is well placed to launch a counterattack with ... f7-f5."
"Although this is good in many lines of the Closed Spanish, in this position it gives Black excellent counterplay."
"For a long time it has been established that Black should not fear this position. Keres himself thought that this move was premature. In fact, the present game seems to show the opposite, and puts the whole Keres variation in doubt."
For me at least, the next step would be to put eyes on the board and play through some games.