What is the "greatest"? Greatest could be the absolute best in terms of some metric. Greatest could be the most times in the top 10/20/25/100 using some metric. Greatest could be the most consistent top performances. Greatest could be ...
Today I am going to
attempt to answer this question: Who is the Greatest NHL Goalie in terms of productivity? So how is goalie productivity measured? In a paper published in the Journal of Sports Economics, David Berri and I came up with a way of measuring NHL Goalie production using a concept called Wins Above Average (WAA). WAA uses save percentage as the main determinant of goalie productivity.
Save percentage is a simple and straightforward way of measuring NHL goalie productivity. Other measures such as, wins (often used) is more of a team measure, while goals against average is also more of a defensive measure. When all else fails, how well does the goal keep a shot on goal out of the net; that is our measure of goalie productivity. You are more than welcome to quibble with this idea, but it is simple and easily justified; so I am staying with it.
WAA is measured as: the absolute value (since a goal against has a
negative effect on team wins) of the marginal value of a goal against
divided by two (since each win is worth two standings points) times, the
number of shots on goal that goalie faces times the difference in the
save percentage of the goalie and the average save percentage of all
goalies for that season.
Given the NHL started to collect Shot Attempts beginning with the 1955/56 season, I have collected all the NHL goalie data (from NHL.com) going back to the 1955/56 season to the present. Then I calculated each season's average save percentage; and then calculated WAA for the nearly 4000 goalies that played in the NHL since the 1955/56 season. Ranking the NHL goalies from highest to lowest results in Bernie Parent to have the highest WAA since 1955/56. Using a GA coefficient of -0.34, yields Bernie Parent's WAA = 12.282 for the Philadelphia Flyers in the 1973/74 season (the "Flyers Win the Stanley Cup" as announced by Gene Hart).