It's funny. When reading Pedersen's book in 1997 I made a note about 10...Qb4 being the best. (I never took up the Leningrad at that time.) I completely forgot about it when reading Kindermann's book. I struggled with this line and couldn't get it right. It's good to have the forum to remind me of my old books.

10 .. Qb4 does look a lot safer for black - thanks. I vaguely tried annoying the black queen rather than a3 (which only really makes sense here in conjunction with e4 etc.) but it doesn't seem to work. 

I guess people just felt the line was dubious and the actual reasons were forgotten somewhere along the line. They are also deeply computerish problems.

Just for fun I decided to see what happened to an immediate 9 e4 - it seems to actually be fairly playable (and it seems not in Kindermann or Biem.).  Even got a few vague traps eg: 9 .. fe 10 Nxe4 NxN 11 RxN Bf5 might have a few problems after 12 Ng5 and then if 12 .. Qf6 13 Rh4 is both bizzare and rather annoying.
(b7 is going.).

I'm pretty sure black has playable lines here though - 10 .. Qxc4 for instance.

bes reply to d4 f5 2bg5???? whats best for black

Partly a question about a line from Kindermann's repitoire book and partly a mild warning this.

I had a look at the line after 1 d4 f5 2 Nf3 Nf6 3 g3 g6 4 Bg2 Bg7 5 o-o o-o 6 c4 d6 7 Nc3 Qe8 8 Re1 (his recommended line for white) and then 8 .. Qf7 9 Ng5. He suggests that this speculative for white however things aren't very clear in a line he gives in a footnote.

8 .. Qf7 9 Ng5 Qxc4 10 Bf1 Qc6 11 Qb3+ d5 12 Bf4!?

I can't remember who he attributes it to but he says that white has compensation and black should be a bit careful. His reccomended (and extremly logical) defence is to play Qd7 and c6 after which I don't think white would have much.

However there seems to be a rather nasty concrete problem with this - 12 .. Qd7 13 e4!? fe!? 14 Bh3! Qd8 15 BxB QxB 16 Ngxe4 ^ Nxd5 or Neg5 pressuring e6. No prizes for guessing that Bh3 was a computer idea: I still find it really very odd that using some tempi to swap off a bishop which hasn't moved and isn't very active works well - black might be in some trouble here.

On move 13 black can try 13 .. h6 but then 14 ed might work out quite well for white (very messy though). 13.. Nxe4 runs into one of blacks main problems here - the d5 pawn hanging to Nxd5 followed by sundry threats.

So perhaps 12 .. Qd7 isn't best. 12 .. h6 is possible when 13 Nf3 threatens Ne5 x g6 etc so maybe 13 .. g5 14 Be5 (threatening Bxf6 & Nxd5 etc) e6. I found a game on chessbase online which reached here. However after 15 Rac1 Qb6 white has a truly annoying cheap trick with 16 Bxc7 when blacks position might be all right somehow but isn't any fun.

12 .. Na6 13 Rac1 doesn't seem to be very effective for black.

So perhaps the best move might be 12 .. Qb6? Then 13 Rac1 or 13 Nb5 Na6 14 Rac1 both allow black to get in his desired c6. So white might have to go in for 13 Nxd5 when at least after 13 .. NxN 14 QxN+ e6 etc black can get d4 so at least is a pawn up. 
White's compensation does seem fairly reasonable here though. I guess 15 Qc4 Bxd4 16 e3 Bg7 (Bxb2 Rab1 is rather a bad looking pin! Bf6 maybe) 17 Bxc7 etc seems plausible.

Have I missed something obvious here? I realise that whites play is dependent on some fairly cheap seeming tactics to stop black getting in a setup with c6 but it seems possible that he can. In which case the line does seem reasonably promising for white.

Kindermann doesn't like the alternatives to Qf7 so this is perhaps a mildly important line.