The off-center shaft design increases “ulnar deviation”, which visually is a more arched wrist position throughout the stroke. This works through the off-center shaft design lifting the hands slightly higher at the address. This position limits the wrist movement and places the shaft in a flush line with both forearms. With your wrists in this position, the putter works as an extension of the lead arm. This effectively takes away the power from the hands and wrists and forces the bigger muscles of the upper body to control the putting stroke.
The flat sides are in a parallel plane to the putter face, making it impossible to grip the putter any other way but with the palms square to each other and the putter face, making the control and aim of the putter face far more consistent for you.
If you don’t control your hands, you won’t be able to control the putter face. The putter head does not move back/ forward/ up/down/ open/ closed without the influence of your hands…..try moving your putter without using your hands…..impossible isn’t it?