These days I am reading Cyrus Lakdawala’s “Play the London System”. It’s an interesting read and I will probably return to the subject.
Our understanding of one opening is often influenced by our understanding (or lack of such) of other openings. I was curious when I saw Lakdawala briefly discard Black’s traditional mainline in the Barry attack (1.d4 d5 2.Bf4 Nf6 3.e3 g6 4.Nf3 Bg7 5.Be2 0–0 6.Nc3 c5 is the relevant London move-order) with the explanation that ‘7.dxc5 transposes to a favourable Reversed Catalan’ and some relatively brief variations. I must admit that the Catalan is not my field of expertise so I had to take a closer look at his variations - in particular as I had explored this line when researching ‘A Killer Chess Opening Repertoire’ (and concluded that Summerscale’s 7.Ne5 probably still is White’s best try):
This is the most popular reply and the only one mentioned in the book although 7...Nbd7!? has been played by Khalifman among others.
The exclamation mark is by Lakdawala and the move probably is White’s best try.
This is clearly most popular. Somewhat mysteriously Lakdawala gives the rare 8...Ne4!? as his main line. After 9.Ncxe4 dxe4 10.0–0 Nc6 11.c3 f5 12.Nb3 of Hodgson-Gullaksen, Stavanger 1989 he concludes that Black doesn’t have enough for his pawn.
9.Nb3 Qb6 10.Nb5!
Again the exclamation mark is by Lakdawala. White has also tried 10.0-0, 10.a4 and 10.Nxd5?!.
What else? Black was threatening ...e5 as well as ...Bxb2.
11...Bxb2 12.Rb1 Bg7 13.0–0 Nc6 14.c4 (Dia)
Not 14.N5d4? e5! 15.Nxc6 bxc6 and Black wins.
So far everything seems very natural if not entirely forced. Now it seems Black has at least two ways to equalize (as a matter of fact Rybka also thinks 14...a6!? and 14...e5 look OK):
A: 14...Bf5 15.Rbd1 Nf6
Or 15...Nb4 16.Qd2 Na6 17.Nc3 Nf6 18.Qc1 Rac8 19.Be5 Be6 20.Bd4 Qb4 = L.B.Hansen-Djurhuus, Reykjavik 1995.
16.Qc5 e5 17.Bg3 Ne4 18.Qxb6
Rybka claims that 18.Qa3 is equal. That may well be right; the position looks somewhat strange and I find it hard to evaluate.
18...axb6 19.Ra1 Rfd8 and in Akselrod-Salinnikov, Tomsk 2003 Black was clearly better thanks to his activity.
B: 14...Nf6 15.Qc5 e5! 16.Bg3 Ne4 (Dia)
a) 7.Qxb6 axb6 18.a3 Bf5 =+ Rogers-Fedorowicz, Groningen 1990.
b) 17.Qa3 and now 17...Nxg3 18.hxg3 Rb8 (18...Rd8?! 19.c5 +/- Klimets-Gerasimovitch, St Petersburg 2002) 19.c5 Qd8 20.Rfd1 probably is a little better for White. However, Rybka thinks that 17...Bf5 as well as 17...Be6 is at least OK for Black.
I have not found a path to advantage for White after 7.dxc5. That doesn't mean there isn't one, but Lakdawala's explanation clearly isn't sufficient for me. Maybe someone who knows more about the Catalan (and consequently more about the Reversed Catalan too) can point me in the right direction?