In ice hockey, the butterfly style refers to a style of goaltending in which the goaltender covers the lower part of the net with his or her leg pads, mainly by dropping down on the knees. Although effective and popular among goaltenders, this style can leave the upper portion of the net more vulnerable than it would otherwise be. The butterfly style derives its name from the resemblance of the spread goal pads to a butterfly's wings.
The butterfly style is often used to describe the newer profly style of goaltending refined by such luminaries as Patrick Roy and made popular in the early 2000's by such goaltenders as Jean-Sebastien Giguere, Roberto Luongo and Henrik Lundqvist. The profly is a more specialized style collection of the butterfly.
The profly requires that the goaltender's leg pads fully rotate 90 degrees when the goaltender drops to the ice on his knees. In this position, the goaltender's pads provide a full 12" (now 11" for NHL-legal specifications) of blocking surface above the ice which presents a wall to the shooter. With the legs flared out in a V shape from the knees, this presents excellent coverage on the ice, deflecting pucks to the corner. Extra padding above the knee, referred to as thigh rise, allows the space between the knees to be closed as the top of the pads meet. This is another attribute of profly goaltenders that is not shared with the older butterfly style. Butterfly goaltenders may land on any of the facings, inside corners, or knee wings and lifts, if so equipped. Profly goaltenders tend to only land on the knee wing and lifts.
Another specialization of the profly is when recovering to the skates, fully upright, to reposition for a rebound or second shot. Rather than picking up the leg closest to the puck, the leg furthest away from the puck is raised, and then pushes the puck-side leg toward the puck. At this point, the goaltender may roll back onto the puck-side skate blade and face the shooter in the familiar ready stance.
There are a number of other recent innovations such as the V-H with which profly style goaltenders identify.
Glenn Hall was one of the first goaltenders to pioneer the use of the butterfly style, while other contemporaries, such as Terry Sawchuk and Jacques Plante, often used the stand-up style. Plante actually cautioned against its use except under certain types of screened shots. However, Vladislav Tretiak's outstanding performance at the Summit Series, and Patrick Roy's success with it in the NHL, helped to popularize the butterfly style. The butterfly style can now be considered to be the most favored goaltending style in the modern NHL.
Pioneers of the profly include Canadian coaches François Allaire and Benoit Allaire, and equipment designer Michel Lefebvre of Koho and RBK fame. Patrick Roy worked with the Allaire brothers and used Lefebvres equipment in the late 1980s.