Well I've completed 2 engines-off correspondence games on chess.com in the meantime, and one conclusion I've come to is that in a couple of cases at least, this line with 9...Na5 and 10...Re8 will merely transpose to other variations.

The first of those transpositions is if White plays 11.d3 and if play then proceeds 11...c5 12.Nbd2 a common position arises that typically originates from 9.d3 and Fischer even won from this position against Spassky in their rematch.

The second of those transpositiions arises if White plays 11.d4 and then responds to 11...exd4 12.cxd4 c5 with 13.d5.  Then after 13...Nd7 a position arises that can be reached via the move order 10...c5 11.d4 exd4 12.cxd4 Re8 13.d5 Nd7 for which I find one example, an email correspondence game between a couple of 2300+ players in 2013.

Going further though, if 14.Nbd2 Bf6, we reach a position that can be reached in this manner: 10...c5 11.d4 Nd7 (Keres' variation) 12.Nbd2 exd4 13.cxd4 Re8 14.d5, and there are an additional half dozen high level games involving 2400+ players, including Nigel Short twice, once with White, once with Black.

Interestingly I was thinking about adopting the Keres' variation, so first exploring the 9...Na5 10.Bc2 Re8 move order may be my gateway.  Will probably pick up the Nigel Davies' book "Play 1.e4 e5" from 2005 which I think has the most coverage of any relatively recent book on the Keres' variation, though the line with 14.d5 did not first get played until 2008 so don't know if it will have coverage of 14.d5

Lauri Torni wrote on 04/18/16 at 09:20:22:



That's what they said about it at the time and to date no-one has taken Stein's idea and refined it into a popular system.

MartinC wrote on 04/15/16 at 09:20:12:


Lutikov continued 11. .. Bb7, which could become a Zaitsev even if that was in the future in 1969.

Comparing it to main lines of the Zaitsev, the Na5 idea isn't always played.

The famous Fischer - Stein game is from the same era and also a type of proto - Zaitsev. That went 9 .. Bb7 10. d4 Na5 11. Bc2 Nc4 12. b3 Nb6 13. Nbd2 Nbd7

Stein's idea, like that in most Zaitsev variations appears to have been to play exd4 and look for activity with pawns on the Queen side. 

George Jempty wrote on 04/14/16 at 03:48:17:



10.d4 and how are you now going to proceed? What's the point?

9...Na5 10.Bc2 Re8 seems like a not unreasonable plan to me: first get White to move his bishop off the a2-g8 diagonal, and only then play ...Re8 when Ng5 no longer accomplishes anything (like a potential draw for a weaker player).  Why is this so rare?  You might say it's anti-thematic, that ...Na5 prepared ...c5, but that latter is still a possibility albeit delayed.

The earliest game I can find with it given my limited resources is Barczay-Lutikov, Sarajevo 1969, 1/2-1/2.  Does anybody know of any earlier instances?

In any case I plan on trying it out next chance I get.  I've got a "engines-off" game going on right now on chess.com but my opponent played the non-critical 12.d3 when 12...c5 seems pretty nearly equal.  Critical seem to be 12.d4 or 12.b4 when I don't think White is getting all that much more of a slight advantage then in a lot of other lines in the Closed Spanish.