Back in the days of shellac lanes, bowlers had to affect the ball to hook, and the Full-roller
was the best way to do it. Balls didn't have offset weights as they do today, but just a pancake weight on the top, where the finger holes would be drilled. So, where today's balls are hooked by the placement of the internal weight and the cover, yesterday's balls were hooked by the finger manipulation at the release.
release was the favored way to produce a hook. The ball was released with the thumb and the middle finger at the same time. At the release, the fingers imparted a side rotation. This gave the ball a full rotation that tracked between the thumb and fingers, but it had very little tilt, if any. Additional hook was given by manipulating the fingers to turn the axis of rotation. Many full-roller
bowlers developed calluses on the index finger sides of their finger nails and the inside of their thumbs in trying to hook balls this way. The hand had the thumb at 10 o'clock and the fingers at 3. Bowler's hands used to be ugly and disfigured because of these calluses. Bowlers like [censored] Hoover were successful with this release, causing the ball to have a down and in trajectory, but fairly straight into the pocket.
When lacquer replaced shellac, the full rollers couldn't roll a hook, no matter what they did. They would fold their fingers at the release, and go into a finger snapping motion to get it to hook. Others rotated their hands radically which caused the ball to spin more.
As offset weights became popular, many full rollers developed more side turn and finger hits on the ball to maintain their hook. Billy Golembiewski is an example of this. His Track
actually moved to outside of the middle finger and inside of the thumb on an angle.
Yes, the full roller Track
rolls the entire length on the ball surface, and between the thumb and the fingers. If a full roller
were to use any conventional finger placement on today's offset weighted balls, the Track
would be over the finger holes.
John Jowdy calls the full roller
one of the 7 ineffective rolls for a strike ball, along with the back up, full spinner and fingers first, end over end, with little hitting power and deflection.