This raise is almost mandatory.

If you purchase the best hand, you increase your equity by about 60%. That's worth about 3BB for an investment of .8BB (Assuming Sb wouldn't fold for 1 anyway).

You only have to be buying the best hand like 1 in 4 times for this to be correct.

Even if you are behind to BB at this point.

Will BB 3bet you when ahead?
If so, you lose .8BB drawing to the nut flush.

If behind you will clear up an average of 3 outs. This will increase your equity by 7%. In a 6.5BB pot that's worth .455BB.

Without the case 8, BB 3bets you WAY less than 50% of the time.

VERY NICE RAISE.[img]/images/graemlins/heart.gif[/img]