2nd Gear

This morning I had my spots lined up for a 2-rail 2nd gear shot. The STANDARD SHOT LINE (SSL) (the point at which you aim, using 2nd gear, where the cue ball will go into the pocket). The 8 ball was frozen on the long rail by an end pocket, with it's front at the point on the rail. The 3rd dot from that pocket is the 2nd gear SSL. The cue ball was another 3 dots away on the other side of the table. To find your aim point the calculation is 1/2--1/2. So from the SSL you first go 1/2 of 3, which is 1 and 1/2 dots, then 1/2 of what is left. 1/2 of 1 and 1/2 is 3/4's dot. That's your aim point to go into the pocket. BUT, the 8 is that slight distance away from the pocket. Trace the path and go down the pocket with your cue tip. Then notice how wide the space is to a ghost cue ball sitting behind the 8. My question to you is do you have to go 1/2--1/2 again?   Lester