Reading the Break starts with gauging the speed at
which your ball is likely to roll enroute to the hole.
The speed of the green and the force of your stroke determine how far your ball will roll. On a slope they will influence how much and when your ball will break.
Except for straight up and down putts on the Fall Line, all putts break one way or the other.
The Skill of Reading the Break is in accurately calculating the amount of curvature on any given putt given the green speed of the day.
The speed of the green is determined by a number of conditions. They are the height of the grass, its texture, the moisture it contains, the grain, the slope, the surface dampness, and to a lesser extent the wind if it is more than a mild breeze.
The ground crew take these conditions into account and set the mowing height to achieve a predetermined speed as measured by the Stimpmeter. This measurement is taken by rolling balls down a ramp on a level section of the green.
For the average golfer the Stimp number is of academic value. Most putts are not level, and it is common sense to expect that the contours of the green will influence how fast a ball travels.
Before any round of golf you should dial in the green speed by using the technique of Reference Putting. This is putting two balls with the same length of backstroke in order to understand just how far they will travel across the surface.
Do this in several directions and this will help your brain to calibrate how much force you need to achieve a certain distance.
The rule of thumb on Reading the Break is that any time you have to stroke the ball more firmly than normal, you should play less break. Put another way the faster your ball is rolling, the less break your ball will take.
Therefore an important consideration in reading a putt is deciding how hard you want to stroke the putt. This is because a firmly stroked putt breaks less than a putt hit at a slower speed.
The amount of break is directly linked to the slope of the green and the texture of the grass, with the slope being the biggest single factor in how much a putt will break.
Fast greens have more break and are more difficult to putt on than slower greens. This is because:
As a general rule downhill putts break more than uphill putts while side-on putts break the most. Wet conditions slow the ball and cancel out much of the break while wind is seldom a factor on slower greens.
During a round there is no exact method to calculate the curvature of a putt and you will have to rely on your eyes. In addition you need a good understanding of the significance of the local Fall Line, and how the speed a ball is travelling across a slope will influence the direction it takes.
As in most aspects of putting the only real way to Reading the Break is experience gained through practice.