This option is a bold use of the pin on the e-pawn to attack the black queen 9...exd5 10.exd5+
& attacking Nc6 also 10…N(c)e5
attacks white’s Bc4 with the queen, so 11.Bb3
staying on the f7 diagonal & also defending d5 11…Be7
stops the pin on Ne5 & allows the ks castle. 12.Bf4
looks good here, pinning Ne5 against the queen this time! 12…d6
defends the knight & removes the pin. 13.h3
forcing the Ng4 away. Play here looks ok for both, but white needs to consolidate being a piece down by using the rooks to attack the open c-file & the d or e-file also, but it could go either way with 1 small mistake.
With careful play from black though, white could be in trouble.
This breaks the black threats on the b8-h2 diagonal. I think many players may play 9…Be7
in reply, going for king safety.
attacking the queen & asserting white’s new dominance on the diagonal 10…Qb6
taking the ½ open central file 11…0-0 & 12.h3
attacking that knight
and white looks to have good chances:
On the face of it 9.Nb5!
looks like a solid, attacking response to the Siberian trap threat. White can possibly get the gambit pawn back, at the expense of a fairly safe black king position.
is rather risky, at least in the line I tried above, but black must delay king safety & deal with some tactical exchanges. Very attacking play from white which could turn sour if he can’t find ways to keep the pressure up.
Maybe there is a better line here & a more convincing way to use the move?
this line can lead to promising play for white, although his king does look rather exposed with g3 & h3 pawn pushes.
However, any option can be risky for white, best avoided altogether if you ask me!
Better to play 6.Bf4
or maybe even an early & bold 6.e5
or, if you insist with playing with fire, 8.Bg5
in the trap line, instead of the rather dubious but habit-formed 8.Qe2
which leads to the trap & the 3 options above.