Explanation of the putting rules for the face on putting stroke.
The USGA had banned croquet-style putting “between the legs”
and also standing on extension of Line of the putt.
But if you stand next to the line of your putt it’s 100% legal that way.
Click on image for bigger view
Is use of a side saddle stroke permitted? Yes, so long as the player does not anchor the club.
View of GP putter
Head view of the face on GP putter
The GP putter is 3 1/16 inch wide.