The nine ball seems locked behind an impenetrable billiards fortress, six other balls blocking it from finding a pocket or even being struck by your cue ball. Yet, you will summon an onlooker to select any one of four pockets at will, before you sink the "magic 9" in their spot of choice, on the first try! See if you can discern how the trick works before proceeding.
The cue ball position to assume is based on whichever pocket is requested (as labeled in the diagram for your convenience). If they call for Side Pocket "6", place the cue ball opposite the 6-ball as shown, or if the fans ask for Corner Pocket "1", line straight onto the 1-ball as indicated, and so on. You simply need to strike a full hit on the object ball.
For Pocket 2, the 3- and 6-balls float aside from impact, and the magic 9 hits off one side of the 8-ball to sink in the corner, and a similar clearance shot is used for another pocket. Determining the precise shape of the semi-circle of balls that works on your particular table takes a practice attempt or two but is worth your effort.
"Power of 9" is a favorite of Nick Varner's trick shot show, and once you learn the gimmick, you can do it as he does, selecting one volunteer to choose the pocket then a second audience member to make the shot on one try. You set the cue ball then whisper in spectator #2's ear to hit the particular ball full on.
You may even wave your magic cuestick over the guest and proclaim, "I have given them of my pool power!" before covering the top of the colored balls with a handkerchief or paper! The trick is that easy to perform!
This is a classic setup shot,a super easy pool trick shot, that harks back at least 70 years in pocket billiards history. Go get 'em!