After the moves 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0–0 b5 6.Bb3 d6, it seems that 7.c3! must be the critical test.
Now d4 is no longer available for Black's knight and 8.Ng5 is becoming more of a threat.
Now d4 is no longer available for
Black's knight and 8.Ng5 is
becoming more of a threat.
This is Black's most popular follow up and removes pressure from the sensitive f7-pawn. In a reply to my 7.Ng5 entry, Phil Adams brought to my notice that Soltis in his new book ' Transpo Tricks in Chess' (Batsford 2007) briefly discusses this move-order. Obviously Bisguier used it mainly as a confusing transposition tool against Robatsch in Hastings 1961, here playing 7...Be7. That allows White to look for ways to omit or delay Re1 (as the e4-pawn is already protected by Bc2), but the White rook will be nicely placed on e1 so it will normally quickly transpose to a mainline Closed Ruy Lopez.
I had a look at 7...g6 8.Ng5 d5 9.exd5 but did not find anything that really looked playable for Black.
7...Bg4 is another active move that keeps open the option to develop with ...g6. Unfortunately it seems White can keep an edge with little risk:
a) 8.Qe2 mainly has historical interest: 8...Be7 9.Rd1 Na5 10.Bc2 c5 11.d3 Nc6 12.h3 Bd7 13.d4 += Stoltz-Alekhine, Salzburg 1942.
b) 8.Re1 is the start of a familiar plan for most players of the white side of the Ruy Lopez. White hopes to demonstrate that the active bishop mainly is a target and will play d3, Nbd2-f1-g3 and only then put the question to the bishop with h3. A relevant game went 8...Na5 9.Bc2 c5 10.d3 g6 11.Nbd2 Bg7 12.Nf1 0–0 13.h3 Bd7 14.Bg5 h6 15.Bh4 Qc7 16.Ne3 Be6 17.d4 Nc4 18.Nxc4 Bxc4 19.d5 b4 20.cxb4 g5 (20...cxb4 21.Ba4 +=) 21.Bg3 cxb4 22.Qd2 with some advantage to White in Unzicker-Bisguier, IZ (Gothenburg) 1955.
This increases Black's central presence, allows him to support his central pawns with ...Qc7 and seems generally consistent with his previous move. Still, b4 doesn't seem to be much of a threat yet, so I wonder if 8...g6 9.d4 Qe7 may be a possibility.
This seems necessary in order to support Black's central presence (but seen in light of the further course of the game you may wonder if 9...Qe7, planning ...g6 is an option).
This appears to be the critical move, and only if Black can pass this test he needs to worry about the alternatives 10.Re1, 10.h3 and 10.a4.10...g6!?
Well, this bishop development was Black's main idea. However, it's worth noting that one of Kuzmin's latest games with the line went 10...cxd4 11.cxd4 Bd7 12.Bd3 Be7 13.Qe2 0–0 14.b3 Nc6 15.Bb2 Bd8 16.a4 bxa4 17.dxe5 Nxe5 18.Nxe5 dxe5 19.bxa4 Bg4 20.Qe3 Be6 when the players agreed a draw even if White had the more comfortable position in Kindermann-Kuzmin, Panormo 2001.
Only this non-stereotyped move can cast doubt on Black's idea. 11.a4 b4 12.cxb4 cxb4 13.b3 exd4 14.Nxd4 Bg7 15.Bb2 0–0 16.Rc1 Nd7 17.Bb1 Qb6 was fine for Black in Vasiukov-Kasparian, Yerevan 1955.
11...cxb4 12.cxb4 Nc6 13.Bb2 Bg7
Actually the optimistic 13...Nxb4 14.Bb1 Nc6 seems playable but after 15.Qc2 Qb6 16.dxe5 dxe5 17.Nxe5 Nxe5 18.Bxe5 Bg7 19.Nb3 0–0 20.Bd4 White's advantage is fairly obvious.
Black's queen is exposed in the open c-file so this is a natural reaction. Black has also tried:
a) 14...Bb7? 15.Bb3 Qe7 16.Rxc6! Bxc6 17.dxe5 Nh5 18.g4 Nf4 19.exd6 +- Bronstein-Evans, Moscow 1955.
b) 14...0–0 15.Bb3 += was our conclusion in 'The Ruy Lopez: A Guide for Black', but on closer inspection it seems that Black has some quite serious problems: 15...Qb6 16.dxe5 dxe5 17.Nxe5 Nxe5 18.Bxe5 Bg4 19.Qc2 Rae8 and now Suetin-Ragozin, (URS Ch) Kiev 1954 was drawn after the moves 20.Qc7 Qxc7 21.Bxc7 Bh6 (this position is equal) 22.Rc6 Bxd2 23.Rxf6 Be2 24.Bd6 Bg5 25.Bxf8 Bxf6 26.Re1 Rxe4 27.Bc5 Bc3 28.f3 Bxe1 29.fxe4 Kg7. However, after 20.Qb2 Black has problems freeing his position.
15...Bb7 16.a3 0–0 17.d5 Nd8 18.Rc3 gives White a clear advantage.
16.Nxd4 exd4 17.Bxd4 0–0 18.Re1 Be6 19.Nb1
Or 19.Bxe6 Qxe6 20.a4 with a small plus for White.
Now White will have some pressure down the semi-open a-file but his b-pawns are weak. I am not sure why White preferred this over 20.Qxb3 which seems to preserve a small advantage.
20...Nh5 21.Bxg7 Kxg7 22.Rc6 Rfd8 23.Nc3 Nf6 24.Qa1 Qe5 1/2–1/2 Vasiukov-Arulaid, Voroshilovgrad 1955.
It seems Black has a slightly harder task to equalize after 6...d6 7.c3 than in the Closed Ruy Lopez mainlines, but that to some extent should be compensated by the element of surprise. It would also be interesting to see a high level game with 9...Qe7.