Quick answer: A three-putt pattern: the first putt finishes more than a meter short or long; the backswing doesn't scale with the length of the putt.
What it does to the ball
Recurring three-putts: the score climbs and the full swing isn't to blame.
Root causes (by frequency)
Reading only the line and forgetting speed (on long putts, speed rules)
The same backswing for every distance
Not reading the slope from the low side to calibrate it
How to fix it
Practice speed only: putt to zones, not holes, aiming to leave every ball inside a one-meter radius
Drills that fix it
The ladder · 15 min · 16 reps
Calibrate speed on long putts Place 4 tees at 3, 6, 9 and 12 paces. Putt to each distance going up the ladder and back down, trying to die each ball at its tee. Count how many finish within one pace and beat your record every session.
Eyes closed · 10 min · 15 reps
Connect the sight of the distance with the feel of the stroke Look at the hole from 5-8 m, close your eyes and hit the putt. Before opening them, call out loud whether it finished short or long, then check. Putting is feel, not conscious mechanics. Ten putts with eight correct calls to level up.
Frequently asked questions
What is "Poor distance control on long putts" in the golf swing?
A three-putt pattern: the first putt finishes more than a meter short or long; the backswing doesn't scale with the length of the putt.
What does poor distance control on long putts do to the ball?
Recurring three-putts: the score climbs and the full swing isn't to blame.
How do you fix poor distance control on long putts?
Practice speed only: putt to zones, not holes, aiming to leave every ball inside a one-meter radius
Sources
Dave Pelz — Dave Pelz's Short Game Bible
Dave Stockton (con Matthew Rudy) — Unconscious Putting