I don't care for LD shafts as such but I am curious as to why one would shoot everything with the same "focal" length. Shots have too much range to confine yourself like that.
I'm not going to go into it again, I would suggest looking into pivot point for a shaft. The benefits are numerous. If you constantly change your bridge length even when forced not to, I would imagine you miss a lot of balls.
Actually I will. All shafts have a point on which they will hit the same point if lined up on a straight shot and rotated for any side spin while keeping the bridge stationary and rotating the back arm(hand) to appy side spin. Of course there are other variables, which can be mitigated in certain ways, but for arguments sake, let's just say that you can hit the point you're aiming at if you bridge at the point on your shaft (pivot point) that hits that point with side spin applied. All shafts have them. LD shafts have pp (pivot points) that are farther back.
Some people use this as an advantage when adjust for sidespin by using BHE (back hand english). That is to say, you aim every shot as though you're going to hit straight center ball and then, while maintaining that bridge position, you manipulate the cue so that it's pointing on the cue ball for the amount of side spin that you want.
There are things that come into play, like swerve (masse), so people that use BHE should raise their bridge for follow and lower their bridge for draw to best minimize this effect.
Now I use a different method for finding the pivot point than that of Dave or others suggest and it is for this reason. Well, first let me say how I find it. I setup various shots and shoot them with extreme sidespin usng bhe and adjust my bridge length until they consistently go in center pocket. It's easier on my table because of how tight the pockets are.
This method isn't best for finding the cue's natural pivot point as it is typically defined but it's better for using BHE because it takes the natural swerve, CIT and deflection that creates multiple variables into account and gives a more day to day usable PP.
There is a second type of PP for a cue and that is for FHE(front hand english). That is instead of rotating the rear arm and keeping the bridge stationary to put the amount of english you desire, you keep your back arm locked and slide the bridge hand (front hand) side to side to apply the english you desire.
It just so happens that they tend to be at the same place. what I mean by that is that if you are bridging for the PP for BHE, typically (if your arm is at 90 degrees at the tip contact with the cue ball) your grip hand will be at the correct point to rotate for FHE, but this should be verified prior to use because it's not always the case.
This definitely comes in handy when you can't bridge at the BHE PP because of an obstructing ball. You can bridge anywhere and slide your bridge for FHE and still effectively use side spin.
Now a quick list of benefits (these are mostly benefits of bridging at the cue's pivot point, not holding the butt for the FHE PP)
1) Stroke forgiveness
a). Since you shot doesn't know if you intended to rotate at contact, it doesn't care and the ball will often be potted successfully anyways.
b). You can use various methods of applying BHE, players in the past have successfully used swiping (twisting the cue sideways just before contact) although I wouldn't suggest it.
2) consistency
a). your body develops muscle memory, the more variables you introduce by varying bridge length, the longer it will take to develop said muscle memory and the more variables there are the more likely failure will occur.
3) BHE
a). The ability to easily adjust for squirt with any cue and use any side spin you want while still striking the ball where you want has so many advantages, it's hard to explain. It's ESPECIALLY important for shots in one pocket. Inside or outside to throw a bank to get out of the way is essential for high level one pocket.
b). being able to more accurately aim for CIT(collision induced throw). Sometimes you don't quite have an available angle because of a ball obstruction. With BHE there's no need to guess, you get to use spin to aim slightly off and throw the ball into the pocket. You still aim as though you were going to just shoot the ball regularly but the squirt sends the cue ball in at a different angle to avoid the obstruction, but the spin throws the ball in the pocket.
There's more but I don't feel like writing a book right now, especially when I started out the post saying I didn't want to answer it again at all...lol.
