The Lie Angle of the Putter in putting is one of the important elements in the delivery of the Putt Calculation. Once you have worked out what the putt needs to do, you then have to apply this to the ball. The sweet spot on most putters is a small area below and at a refracted angle from where the shaft attaches to the putter head.

The BI 3 Putter has a very LARGE sweet spot,. This is due to the shaft connecting to the rear of the putter and transfering the power via the arch to all the face from either side. This projects the sweet spot over the entire face.

The speed of the putt is delivered via the stroke through the putter face and the Putt Calculation requires a specific speed to make the ball follow the Putt Visualisation line. The bigger the sweet spot the greater the chance of delivering the correct power to the putt and avoiding mis-hits.

The design features of the BI 3 Putter allows you to maximise the Putt Calculation via a Precision Putter and to become a better putter all round. 

See here for Design features BI 3 Design Features & User Benefits

Review the Putt Calculation here Putting Calculations & Design Concepts