A slap shot is generated by winding the stick back well behind the puck, then swinging through and striking the ice just behind it before contact, using the stick's flex to store and release energy into the shot. It trades the quick release of a wrist or snap shot for raw velocity — a slower windup in exchange for a much harder shot on net.
The technique wasn't always welcomed. In hockey's earlier decades, some coaches actively discouraged the slap shot, viewing it as an inaccurate, low-percentage "show-off" play compared to the quicker, more controlled wrist shot most players relied on.
Bobby Hull is widely credited with popularizing and perfecting the slap shot through the late 1950s and 1960s with the Chicago Blackhawks. His shot was regularly described as the hardest in the league, with period estimates putting it well over 100 mph — measurement technology of the era wasn't exact, but the reputation was well earned. The nickname "The Golden Jet" captured both his blazing skating speed and the shot that came with it.
Equipment has pushed the slap shot even further since then. The shift from wooden sticks to composite construction gave a much wider range of players the ability to generate serious power consistently, not just a handful of elite outliers. Today's hardest recorded shots at NHL All-Star skills competitions regularly clear 100 mph, with some approaching 110.
What started as a shot some coaches actively tried to coach out of their players became, within a generation, one of the most feared weapons in the sport.