Rule (Dr. Dave TP 7.2): T = D − F — origin direction D, 1st-rail diamond F, 3rd-rail arrival T. Running english, aiming through the diamonds.
Blue = origin direction numbers (D) · Orange = 1st-rail numbers (F) · Red = 3rd-rail numbers (T).
Along the long rail D changes 0.5 per diamond; up the short rail, 1 per diamond.
Aim through the circled diamond, not at the cushion spot opposite it —
the diamonds sit behind the cushion nose, so the ball actually bounces a hair
short of the diamond (the white dot). 3rd-rail target numbers are true cushion contact points.
The cue ball just lies somewhere on the track: D is read where the dashed line
behind the ball crosses the blue scale, exactly as in the TP 7.2 figure.
Path is schematic: the system assumes medium speed with natural running english.
Real tables run a bit long or short, so calibrate a half-diamond on yours.