At my schools we preach the importance of the 20-foot putting stroke since 20 feet is the most common putt length in golf. So any student of mine facing a 15-foot putt on the course will preview some small adjustment to that 20-foot reference stroke during their pre-putt routine factoring in the other conditions of the putt that are computed as you read the green such as slope break grain wind etc.
You OWN a pre-putt routine. That’s good — it’s essential to long-term success on the greens. I bet however that your routine (what you do after you’ve marked cleaned and replaced your ball) fails to include a preview stroke which is a practice stroke made with a clear intention of matching the length of your stroke to the putt you’re about to attempt.
Missing the green left or right will demand hitting a flop shot for your third — other short-game shots just won’t hold the green. And hitting lobs in a gusting wind is no picnic. You can sail long or come up short without notice.
One of the things that separates Tour players from the rest of us is that the former are intimately familiar with their games. They know how different shots will unfold regardless of where the ball is sitting especially around the green (where difficult lies abound). Not surprisingly that’s where weekend players tend to cough up strokes.
You can’t dominate with your putter if you don’t know how to aim it correctly or how much break to play. Nail these fundamentals first. If you hook or cut-spin your putts your chance of success goes down. If your putts roll off the face in the same direction your putter is heading immediately after impact that’s good. If your putter moves one way and the ball another you’ve got problems.