The lines on your putter critical to the aim scenario. Most golfers assume that you need to have lines on the putter to ensure they aim straight. We see lines on airstrips, highways, railway lines, and race tracks, and it makes sense that we think that they are helpful. However lines can exert both positive and negative effects depending on how your eyes interpret them. Not only is it a question of whether or not to have aim lines, but also where they should be placed and how many should be used.
Lines, in general, tend to make golfers aim left.
The farther back the lines are on the putter, the more they will tend to aim you left.
Lines near the top-line influence aim less than those placed nearer the bottom cavity.
An absence of lines tends to create a right aim bias.
The reason for these biases is that lines and the way they’re patterned affect which part of the putter you look at. If there are more lines on the back cavity than on the top-line, you are more likely to look at the back cavity. If there are more lines on the top-line than the back cavity, your attention will be drawn to the front of the putter. This will in turn change your perspective of the hosel, putterhead — everything.
Includes : Wrench, screws, and hard shell carrying case