some thoughts on decision making
This is how to determine (IMHO), which side of the 8 will bring you to better results more often...
1st:
Which side of the 8 has a bigger landing area? In this case with the 8 ALMOST in the middle of the head rail, you can see, the triangles to land in (transparent cueballs mark the worst points from maybe a chalk away or being about 2,5 diamonds on the rail). Easy to see, that this favours the right side of the 8.
2nd:
Assuming, that for a comfortable bridge, the cueball should be about a diamond away from the long rail to pocket the 8 easily, we're faced with this situation:
you've got perfect position on each side, or you've missed perfect position in angle (shallow or steep).
Try to get into position for the 9 from each point...
... I think, this will also favour the right side of the 8!
3rd:
You're faced with this situation. You've missed perfect position by speed and you're hooked on the rail. Also with perfect angle, shallow or steep angle.
Try to get position on the 9 from these points will favour the right side of the 8 immensely!
If you're getting to the same result, that the right side of the 8 will be the favourite in all 3 terms, it's time to choose a "BALL IN HAND" for the 7, to hopefully get the best position on the 8...
... here are 4 easy ways to get there (a good way already shown by "branpureza"):
By the way:
after an (hopefully) easy 8-ball, being short sided on the 9 will be perfect!!!
That's my in my opinion the easiest way out...