Practising alone lets you control the starting position, but it also makes it easy to forget misses or change the setup. Use explicit counting rules instead of treating every solo session as a match.
Make the reset reproducible
Record ball centres with a diagram or permitted placement aid. Check which ball is yours and return all balls, not just the one that moved most. Save the layout in 3Ball if useful. Allow for placement uncertainty; do not mark or attach anything to a physical cloth without permission.
Keep all fixed-position attempts
Choose a fixed attempt limit in advance. Count every attempt and record make/miss plus the first observed error. A run of ten successes selected after unlimited misses is not a ten-shot success rate. Simulator repeats with identical inputs are model checks, not evidence that your hand can repeat a stroke.
Define the open-play block
If you invent a “ghost” opponent, write its scoring rule before starting and keep it unchanged. There is no official universal ghost format for this exercise. Keep normal points/innings separately from ghost scores and from fixed-layout percentages. Decide in advance what happens after a miss rather than moving the balls to make the next shot easier.
Leave feedback for next time
Photograph or save one troublesome layout, note the intended route and identify what the replay or observation did not show. Revisit it on another session before consulting your old solution. Ask a coach about unresolved physical execution. No compulsory session split, warm-up duration or streak count is claimed to be the cause of improvement.