Evaluating goalies is very important, because you don't want to end up paying superstar dollars to a guy who is an average-level talent. Which is exactly the mistake the Sabres made over the off-season when they resigned Ryan Miller to a 5-year, $31.25 million deal.
Miller has a reputation as one of the league's better goalies, but the perception isn't quite in tune with reality. Since the lockout, Ryan Miller is 5th among all goalies in wins, but tied for 23rd in shutouts, 18th in GAA, and 18th in save percentage.
In the playoffs over the same period, Miller has the most games played and the most wins, but he is just 10th in GAA and 11th in save percentage, as well as tied for 12th in shutouts.
What about his team? The Sabres score a lot of goals, does that mean they often leave their goalie out to dry? Apparently not. Alan Ryder has measured the Sabres to be a better-than-average team in terms of shot quality in each of the last three seasons. According to his marginal goals from goaltending measurement (which includes shot quality), Buffalo's goaltending ranked 17th in 2006, 11th in 2007, and 24th in 2008.
Although they regressed last year, the Sabres have generally been a strong team in front of Miller. With their backup goalies in the net, Buffalo is 38-20-6 over the last three seasons, for a .640 winning percentage. Miller's win percentage? .635.
Ryan Miller has done little in his career to prove that he is anything other than an average starting goalie. The Buffalo Sabres overpaid substantially for his services, probably mostly as a result of his high win totals. Having said that, there is a possibility that the 28-year old Miller could improve over the next 5 years, but he would have to improve quite significantly to earn his hefty paycheque.