Most golfers judge it instinctively. Instinct and feel remain key factors. But the concept of distance calibration can also be applied to putting in order to help you gauge the correct force to use. I suggest trying my “benchmark stroke” system which enables me to be effective in this area and rarely concede three putts. I use the amplitude of the swing on my putter, which reaches the tip of my right foot (I have a relatively wide stance). This generally allows the ball to roll 6 metres. Given that I always have the same tempo, I achieve different distances by altering the amplitude of my swing. This system has the benefit of acting as a ‘pseudo Stimpmeter’ (a device greenkeepers use to measure the speed of greens) as, depending on that day’s greens, I can see what distance my benchmark stroke gives me on a flat green. Instant feedback! This method also has the advantage of “aligning” me and combatting any lack of instinct or feel. I actually think it helps me hone my instinct.