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 March 25, 2009 Howe and Why Quality Starts by Robert Vollman Printer- friendly Contact Author
 In his recent analysis of Martin Brodeur and the best goalies in NHL history, Tom Awad remarked that “wins” are among the least insightful statistics when evaluating goaltenders. “A goaltender’s job is to block shots; wins, shutouts and even Stanley Cups are a secondary consequence of successfully blocking shots. A goaltender whose team is losing 4-2 and suddenly scores 3 goals is credited for a win, even though he had little to do with the victory other than not letting the game get further out of hand; similarly, a goaltender who loses a tight game 1-0 probably played very well, but gets neither a win nor a shutout for his efforts.” What if we could replace the win statistic with something more insightful? Let's introduce the Quality Start, which would be awarded to goaltenders based on their ability to keep the puck out of their own net, regardless of whether their team scored enough goals for them to win. Quality Starts are defined first and foremost by successfully blocking shots, which are usually referred to as Saves. Evaluating every single game this season, the median save percentage of a starting goalie is .912 percent. Successfully defending the net from goals .912 percent of the time can be defined as a Quality Start. The following table demonstrates that the odds of a team winning become very high when their goalie stops a higher-than-median percentage of shots, very low when the goalie fails to stop at least 88.5% of shots, and is essentially even in the middle. ```Save percentage Winning percentage 0.913 or better 0.777 0.900-0.912 0.536 0.885-0.899 0.503 0.884 or worse 0.246``` To further refine the definition in that average range, we will award a Quality Start among goalies stopping between 88.5 percent and 91.2 percent of shots, depending on how many goals they let in. Since this is based on the number of shots the goalie faced on a particular night, which is largely outside the control of a goaltender, it may seem unfair. The idea is that on nights when the goalie is not up against a lot of shots, it is still considered a Quality Start when he's stopping at least an average number of the shots on goal. ```Goals allowed Winning percentage Under 3 0.727 3 0.140 Over 3 0.397``` It's quite interesting to note that in games where the goalie is stopping an average number of shots, a team is actually more likely to win when the goalie surrenders more than 3 goals as compared to when the netminder let in exactly 3. Based on these two parameters, a Quality Start is defined as any start in which the goaltender's save percentage is .913 or better, or at least 0.885 percent, but allowed fewer than 3 goals. Looking at every game this season, Quality starts have resulted in an actual winning percentage of 0.775, while non-Quality Starts have a winning percentage of only 0.325. Here are the league leaders in Quality Start percentage among goalies with at least 10 games started, followed by the league trailers. ```Goalie GS QS QS% Yann Danis 21 16 0.76 Tim Thomas 48 33 0.69 Henrik Lundqvist 60 40 0.67 Martin Brodeur 20 13 0.65 Pekka Rinne 39 25 0.64 Cristobal Huet 38 24 0.63 Jonas Hiller 29 18 0.62 Ryan Miller 50 31 0.62 Manny Fernandez 23 14 0.61 Evgeni Nabokov 51 31 0.61 . . . Karri Ramo 14 6 0.43 Jean-Sebastien Giguere 42 17 0.40 Mathieu Garon 15 6 0.40 Manny Legace 28 11 0.39 Andrew Raycroft 23 9 0.39 Michael Leighton 13 5 0.38 Johan Hedberg 21 7 0.33 Chris Osgood 37 12 0.32 Ondrej Pavelec 10 3 0.30 Pascal Leclaire 12 3 0.25``` The Quality Start gives us insight into this season's NHL goaltenders that most consistently give their teams a chance to win, so it's no surprise to see goalies like Lundqvist and Miller at the top and Atlanta's back-ups at the bottom. It's also no wonder that Boston and San Jose are at the top of the league with their goalies playing that well, but it looks like Detroit is doing it on their own. We can also see the sharp contrast between Anaheim's two starting goaltenders, given that Hiller has more Quality Starts than Giguere despite starting 13 fewer games. Is anyone else surprised to see Yann Danis at the top? Imagine if the Islanders had used him sooner, or if he were playing for one of the contenders. As it stands, The Islanders have lost 6 of his 16 Quality Starts. A Wasted Quality Start is defined as any Quality Start that the team goes on to lose in regulation time, and the top two in the league right now are Islanders (minimum 10 Quality Starts). Ilya Bryzgalov of the Coyotes and two past-or-present Kings round out the top 5. ```Goalie QS WQS WQS% Yann Danis 16 6 0.38 Joey MacDonald 20 7 0.35 Jason LaBarbera 12 4 0.33 Ilya Bryzgalov 31 9 0.29 Erik Ersberg 14 4 0.29``` By contrast, the San Jose Sharks took full advantage of Evgeni Nabokov's 31 Quality Starts – not a single one was wasted. No other goalie with at least 14 Quality Starts hasn't had at least one Wasted Quality Start. The opposite of a Wasted Quality Start is a Bail-Out, which is defined by being awarded a win despite failing to achieve a Quality Start. Among those with at least 10 non-Quality Starts, the league leaders include two Wings and two Bruins behind Brodeur's injury replacement Scott Clemmensen. ```Goalie NQS BO BO% Scott Clemmensen 18 10 0.56 Ty Conklin 16 8 0.50 Chris Osgood 25 12 0.48 Tim Thomas 15 7 0.47 Manny Fernandez 11 4 0.44``` It pays to play for a great teams because even when you don't play well enough to win, your team is still picking up 2 points half the time. Alex Auld wishes he was playing for any of these three teams instead of the Ottawa Senators, who are yet to bail him out of any of his 15 non-Quality Starts. The Quality Start is by no means as insightful a statistic as Save Percentage or Tom Awad's GVT. However, it is certainly more useful than wins because it is awarded only to goaltenders that play well enough to win, regardless of whether they're bailed out of their poor play or whether their great efforts are wasted by a lack of scoring. Furthermore, one bad start may seriously damage your Save Percentage or GVT, but your Quality Start percentage will still reflect how often you've given your team a chance to win. Keep an eye on Yann Danis of the New York Islanders and watch out for the Boston Bruins, along with the Detroit Red Wings in the post-season this year. Afternote: Is there a similar statistic we can apply to goalies that come in relief of a struggling or injured starting goaltenders? We could, but there are only 7 goalies so far that have come in relief at least 5 times this season and among them, only Chris Mason managed to either hold a win or be awarded a win himself. He was one of only 11 goalies to have earned a win in relief and another six goalies have held on to the starting goalie's win. It's interesting that no goaltender has both a win and a save nor two of either on the year. ```Goalie Relief appearances Josh Harding 8 Curtis Joseph 7 Jonas Hiller 7 Chris Mason 6 Curtis McElhinney 5 Johan Hedberg 5 Tobias Stephan 5``` Robert Vollman is an author of Hockey Prospectus. You can contact Robert by clicking here or click here to see Robert's other articles.