Thx Patzernoster,

To recap the discussion sofar.

9....0-0 leads to a position with equal chances

9....,Nc6 opens up a lot of interesting possibilities:

I.) 10.Bxd5,Qxd5 11.Nxc6 Qxc6! =+ (11...bxc6 Short-Howell)

II.)10.Nxc6,bx6 12.Bxd5,cxd5=+ (11...Qxd5, Short-Howell)

III).10.Nxf7,

----A 10...Kxf7 11.Rxf4+,Ke8 12.Qe2+,Nce7 13.Bxd5,Qxd5 is murky

----B 10...Qh4! 11.Qe1+,Qxe1 12.Rxe1,Kxf7 13.Bxd5+,Kg6 = is OK for Black

IV) 10.Bxf4,Nxf4 11.Bxf7+,Kf8 12.Nxc6,bxc6 13.Rxf4,Qd6 is better for Black

V)

**10.Nc3! **(Patzernoster makes a lot of sense)

---A

**10...Bxe5** 11.dxe,Nxc3 12.Qxd8+ looks about equal

---B

**10....Nc3 **11.Bxf7+ is more interesting:

----B1. 11....Ke7?! 12.bxc3,Bxe5 13.Bh5! looks better for white

----B2. 11....Kf8! 12.bxc3,Bxe5 13.Bxf4!,Bxf4 14.Rxf4 and white has sufficient compensation: see diagram

Best is 14...Kg7 when white can force a perpetual with 15.Rxg4+!,Bxg4 16.Qxg4+

I dont trust (for Black):

14...Qd6 15.Qf1 +/- or 14...Qxh4 15.Bc4+,Ke7 16.Qf1 +/-

**All in all I would say that 9....0-0 iso 9....Nc6 is the most sensible OTB choice.**