Glenn Hall is generally thought to be the first goaltender to react to shots by dropping to his knees. This was remarkable because he did it without a mask. Other contemporaries, such as Terry Sawchuk and Jacques Plante (who, while not having invented the goalie mask, is credited with having popularized it) relied mostly on the stand-up style. Plante actually tried the butterfly style when sharing goaltending duties with Glenn Hall in St. Louis, but cautioned others against its use except under certain types of screened shots. Hall's innovation was improved upon later in the 1960s and 70s by Roger Crozier and Tony Esposito. In spite of their success, the butterfly fell out of favour until the emergence of Patrick Roy in the mid-1980s. This new, modern butterfly style has been referred to as the "profly" style.