GAP WEDGE

A 'gap wedge' is a type of golf club used to hit a shot with higher and shorter trajectory than a pitching wedge.
During the 1990s, improvements in manufacturing enabled recreational golfers to hit iron shots much more accurately. Lofts for clubs are typically 45 to 48 degrees for a Pitching wedge, 50 to 54 for a Gap Wedge, 54 to 58 for a Sand Wedge (although 56 is very common), and specialty wedges such as the loft wedge from 59 to 64 (although 60 degrees is common). Consequently, manufacturers delofted their irons to allow for greater distance. The primary consequence of this delofting reduced pitching wedge loft from nearly 50 degrees to 40-44 degrees. This left a huge gap between the pitching wedge and the sand wedge, which is typically 54-58 degrees. To address this issue, golf manufacturers began marketing gap wedges.
Gap wedges have a rather wide range, but typically range from 50 to 54 degrees. In the lower range, from 46 to 50, a wedge typically has no flange on the bottom--that is, no "bounce." It is often called an "approach wedge" and is sometimes labeled "A." This wedge is used primarily from the fairway and favors firm lies.
On the other end of the range, some manufacturers market wedges with very high bounce angle and loft angles between 50 and 54 degrees. Such a wedge can be used as the "approach" wedge, or it can be laid open to scoop through sand to liberate a ball from a bunker as one would with a sand wedge. It is also useful when the ball is buried in deep rough, and it prevents the club from snagging in a sloppy or soft fairway. This "dual wedge" is sometimes labeled "D."
The compromise gap wedge is 52 degrees and has a slight bounce angle. This allows usage in rough or a sand trap where the ball is "sitting up" a little. However, a typical amateur golfer will usually use a 52-degree wedge from the fairway to hit a high-lofted shot from about 80 yards, but most professionals hit 52-degree wedges 100 yards.
Fifty-two-degree wedges carry a bewildering variation in labeling. Most manufacturers simply label it with its angle. Some manufacturers call it an "all wedge" and label it with "A," lending confusion between it and approach wedges. The Ping Company labels its gap wedges with "U." It is unusual to find a gap wedge labeled with "G."
Regardless of labeling, golfers employing a gap wedge should be aware of its precise angle. For example, if one uses a slightly delofted sand wedge, then it is pointless to carry a 52 or 54 degree gap wedge. However, the wide variation of gap wedges allows golfers to be creative. For example, one could carry gap wedges at the two extremes (approach and dual) and forego the traditional sand wedge.