From same website: For the 1981-82 season, the Philadelphia Flyers introduced the decade's most radical idea -- long pants, as modeled here by Brian Propp. The idea behind the new pants, manufactured by Cooper under the name Cooperall, was to create a faster, lighter uniform, with lighter padding underneath. The pants did make the skaters faster; unfortunately, they were also faster whenever they took a spill and would crash very hard into the boards. The Hartford Whalers joined the Flyers in wearing long pants the following season. At the end of the 1982-83 season, the NHL outlawed the long pants, causing both the Flyers and the Whalers to revert back to the old faithful, time-tested short pants.
Makes it sound like pants made players slide across the ice faster than the shorts did. I guess but it seems like you'd be sliding on the same part no matter what you were wearing.
Those HAD to be the ugliest things ever in hockey! It made NHL players look like beer-leaguers in sweats! Of course, it didn't help that the 2 teams that used them had a couple of the ugliest jerseys ever, too!
A couple of the high school teams in my area wore them for 2 or 3 years, and the players I talked to said they were REALLY hot compared to traditional hockey pants (or "breezers"), and they were glad to be rid of them.