Having only two balls left on the table makes positioning for the 9 a lot easier. Especially when you need to have the cue-ball travel all around the table to get that positioning.
Take a walk around the table.
Having an easy shot on the 8 in the side pocket is nice as long as you are able to get to the 9 ball afterwards.
Hitting this lightly will leave you on the wrong side of the table.
Adding a lot of low outside english, (when faced with this angle on the object ball) will carry the ball all around the table giving you a shot on the 9.
It is important that you understand the path the cue-ball takes after sinking the 8. You may be faced with a similar shot and have other balls on the table at the time. Being able to picture the path when using low outside english will keep you from running into intervening balls.
Attention: Don’t hold back, hit this shot firmly and hard. Speed control and hitting the cue-ball hard are needed for this shot. Hitting too hard could leave you in the corner pocket.