After 1.e4 c5 2.Nf3 d6 3.b3 Nf6 4.e5 dxe5 5.Nxe5,

it looks like Black can win a piece with 5…Qd4

http://www.france-echecs.com/diagramme/imgboard.phpfen=rnb1kb1r/pp2pppp/5n2/2p1N...
                              after 5...Qd4

Then after 6.Bb2!? Qxb2 7.Nc3 the black queen is trapped, but not facing immediate danger.

Here 7...Bf5 looks like Black's best try.

Trying to extract the queen immediately with 7...Qa3 doesn't seem to work: 8.Bb5+ Bd7 9.Nc4 Qb4 10.Bxd7+ Nbxd7 11.a3 and the queen is lost.

8.Bb5+ Nbd7 9.Rc1 Ne4 10.Nxd7

10.Bxd7+? Bxd7 11.Nxd7 Nxc3 12.dxc3 Qxc3+ and Black is winning.

10...0–0–0

10...Bxd7? 11.Bxd7+ Kxd7 12.Rb1 Qa3 13.Nxe4 and White wins back the piece with a big advantage.

11.Nxe4 Bxe4 12.f3

After 12.0–0 Rxd7 13.Bxd7+ Kxd7 I gotta prefer Black.

12...Bf5 13.Nxf8 Rhxf8 14.0–0 Qd4+ 15.Rf2 Kb8 16.Bc4 and White has won back the piece, but Black does not look worse.

So 5…Qd4 looks risky, but maybe playable.  If there is a major hole in my analysis, however, it may also be a blunder!  Since 5…Qd4 doesn't actually win a piece or lead to a huge advantage, it's not a refutation and I might look somewhere else for Black's 5th move.

Here's a game showing how GM Suba handled the position:

Terreu Serra-Suba
Badalona op Badalona (2), 1994
1.e4 c5 2.Nf3 d6 3.b3 Nf6 4.e5 dxe5 5.Nxe5 e6 6.Bb2 Be7 7.Be2 0–0 8.Bf3 Qc7 9.0–0 Rd8 10.a4 Nd5 11.Na3 a6 12.a5 f6 13.Nec4 Nc6 14.Bxd5 exd5 15.Nb6 Rb8 16.Qf3 Be6 17.Rfe1 Bf7 18.c4 d4 19.Nd5 Qd6 20.Nxe7+ Nxe7 21.Qg3 Nc6 22.f4 Nxa5 23.Nc2 Qb6 0–1

---

Edit: After 5…Qd4 White can avoid saccing a piece with 6.Bb5+ Nbd7 7.Nc4 (looking at the position again I see simply 7.Nxd7 followed by 8.Nc3 also avoids saccing the piece - I guess this was Willempie's point which I was too dense to pick up on right away.  )

The point is that after 7...Qxa1? 8.Bb2 Qxa2 9.Bxf6 gxf6 10.Nc3 the queen is trapped.

7...a6 8.Bxd7+ Bxd7 9.Bb2 Qe4+ 10.Ne3 e6 which led to a draw in Sibilio-Vazquez, Rome 2005.  I don't think this line looks dangerous for Black, however.

Hello,

The line Willempie suggests has been played, twice maybe, but they haven't tried sacing the Ra1 yet though...

Bye John S

p.s make that played loads of times, forgot had a ELO filter on...

Hello,

The line you mentioned looks fine for black, but since Nf3 played early don't see what's wrong with playing Nc6, followed quickly by e5 keeping bb2 firmly under control. Maybe worred about Bb5 in that case?
          Also there are other threads, where b3 sicilian is discussed on this forum, which might be worth browsing.

Bye John S