Putter

It is differentiated from the other clubs (typically, irons and woods) by a clubhead with a very flat, low-profile, low-loft striking face, and by other features which are only allowed on putters, such as bent shafts, non-circular grips, and positional guides.

The putter is the only club that may have a grip that is not perfectly round; "shield"-like cross-sections with a flat top and curved underside are most common.

The introduction of investment casting for club heads allowed drastically different shapes to be made far more easily and cheaply than with forging, resulting in several design improvements.

With a normal putter, the player has six degrees of freedom: hands, wrists, elbows, shoulders, waist and knees, all of which can be moved just slightly to affect the path of the ball and likely prevent a putt from falling in the cup.

German professional golfer Bernhard Langer is famous for having such a severe case that he once needed four putts to hole out from within three feet of the cup.

A long putter is even longer and is designed to be anchored from the chest or even the chin and similarly reduces the impact of the hands, wrists, elbows and shoulders.

Their use in professional tournaments is hotly contested; Jim Furyk and others on the pro tours including Langer and Vijay Singh have used belly putters at some point with a marked improvement of their short game, while players like Tiger Woods and officials like former USGA technical director Frank Thomas have condemned it as conferring an unfair advantage on users.

[5] In November 2012, a proposed change for the 2016 edition of the rules of golf was announced, which would forbid players from anchoring a club against their body in any way.

[6][7] Notable players affected include Adam Scott, Tim Clark, Kevin Stadler, Keegan Bradley, Webb Simpson, Carl Pettersson and Ernie Els.