kylemeister wrote on 10/14/13 at 14:57:39:


But 6...Ba6 isn't exactly forced... Looking thru the games 6...Qa5+ 7.Nc3 Bb7 seems to score well too, but Martens preferred 6...e6!?

Occasionally, he held a few lectures on his different opening ideas here in Malmö, and his favourite game to show was Sosonko-Schüssler, Rolf and Harry probably analysed the Kamtchatka many times together in the early 80s.

Thanks for the interesting replies. 

4.Nc3 b5 5.cxb5 axb5 6.Nxb5 Ba6 7.Nc3 is indeed a Benko proper, but that's fine with me. Black has avoided some sidelines this way.
I believe most Benko players prefer playing against the main lines, even if those are more challenging than say 5.b6 in the Benko move order.

@TalJechin:
Thank you for pointing out that Martens idea with e5 and Bd6. This line looks a bit artificial, but really could be worth a try.
If Black can play e5, Bd6, Bc7, Ba5 and d6, before White gets anything going on the kingside, Black has some kind of Czech Benoni without the "bad bishop".
Furthermore this idea more or less rules out Avrukh's line with 6.a5. That pawn would simply come under fire.
I quite like this, but I'll have to check if White can take advantage of this rather slow set-up by Black.

However, Milov's 4...e6 5.Nc3 Bd6 looks like the most flexible way of dealing with 4.a4.

Fascinating stuff.
I hope we can collect even more ideas.

LeeRoth mentioned a transposition to the Modern Benoni. That's interesting, too. Are there any lines where the early inclusion of a6 and a4 is bad for Black?
Obviously, Black cannot play the manoeuvre Na6-Nc7 anymore.

But 4. Nc3 b5 5. cd ab 6. Nxb5 Ba6 7. Nc3 is a Benko proper.

This looks like the sort of line that objectively doesn't have any advantages, but gains a few minutes on the clock and might make the opponent's usual system against the Benoni less effective. For instance, someone who only plays the 6.Nf3/7.Bf4 setup against the Modern Benoni might be cheesed off by this move order.

Does anybody know where to find something about the Benoni variation 1.d4 Nf6 2.c4 c5 3.d5 a6 from Black's point of view?

This line (also called the Kamtchatka Varaiation) was explored by Rolf Martens from Sweden some 50 years ago.
I found an article by Jesper Hall in New in Chess Magazine 99/8 (so this might be a bit dated) and on Thomas Johansson's Site (hem.passagen.se/tjmisha/) there are some games, but that's all I could find.

I think this line could be a nice surprise weapon and especially a good transpositional tool.

After 4.Nc3 b5 the game will most likely end up in some kind of Benko Gambit, but White cannot play for example the declined version 1.d4 Nf6 2.c4 c5 3.d5 b5 4.cxb5 a6 5.b6 anymore which might be theoretically ok for Black but still spoils some of the fun. The Benko Gambit declined is quite popular at club level, so I like the 3...a6 line here.
Or are there better moves for White after 1.d4 Nf6 2.c4 c5 3.d5 a6 4.Nc3 b5 than 5.cxb5?

After 4.Nf3 an interesting option was already pointed out by Martens himself. Black can play the Snake: 4...e6 followed by 5...exd5 6.cxd5 Bd6!?
As the critical line against the Snake runs 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 Bd6 6.e4 this transposition might be a good thing for Black.

Most White repertoire books (Watson, Avrukh for example) recommend 4.a4 against the Kamtchatka Varaiation.
Black has two main options:
a) 4...e5 was the original idea, going for a Czech Benoni with Be7 or a closed Benoni with g6 and Bg7.
I'm still not sure whether the inclusion of the moves a6 and a4 is good for Black. Any comments?
Avrukh gives 4...e5 5.Nc3 d6 6.a5!? Be7 7.e4 0-0 8.h3 as dangerous for Black
b) 4...e6 5.Nc3 Bd6 has been played lately especially by Leonid Milov with success, but doesn't White have more aggressive options in this Snake than after 4.Nf3 ?

My main question is:
Is the early inclusion of a6 for Black and a4 for White favourable for White or for Black in
I) the Czech Benoni
II) the Snake
III) the Modern Benoni?

Does anybody in this forum have experience with the Kamchatka Variation?