Saturday, March 17, 2007

Playoff Goalies - Ability to Steal a Game

Game-stealing ability is something that is very rarely quantified. It is often assumed that any goalie who is good is also proficient at stealing games, and you won't be able to watch a game involving a top level goalie without broadcasters doing their best to convince you of that point. However, the numbers indicate that goalies differ substantially in terms of how many games they actually do steal or how well they do while being outshot, even despite a similar overall performance. Just because a goalie is good, does not mean they necessarily win a lot of games singlehandedly for their team. And conversely, there are a number of mediocre goalies that seem to every now and then elevate their game enough to pull out a surprising win for their teammates. So rather than going on reputation alone, I will dig into the numbers to try to identify the goalies that really are a threat to steal victory from the jaws of certain defeat.

Stealing a game is somewhat subjectively determined. It is generally assumed to be a situation where the other team is fully deserving of the victory because of its dominant play, and it is only the goaltender's individual contribution that turns the result around. That implies a team that is outplayed, and teams that are outplayed tend to get outshot. A goalie could theoretically "steal" a game with even shot totals if he faced much harder shots (for example, more power plays, more breakaways, more odd-man rushes, etc.) than his counterpart, but I do not have shot quality data for playoff games.

To rate game-stealing ability, therefore, we will turn to stolen wins, or wins when outshot by 10 shots or more. Since some teams are outshot more often, I will also calculate the winning percentage when severely outshot to measure the goalie's effectiveness at stealing games. I also have a statistic called "slim chance games", designed to calculate the number of times when an outstanding goalie would be expected to lose to a replacement level opponent simply because his team was outshot. "Slim chance wins" are wins in such games, and they will also be considered in the analysis.

Stolen wins:
Roy 18, Cujo 14, Hasek 11, Belfour 10, Brodeur 3

Times outshot by 10+ shots:
Roy 33, Belfour 28, Cujo 24, Hasek 17, Brodeur 9

Winning % when outshot by 10+:
Hasek .647, Cujo .583, Roy .545, Belfour .357, Brodeur .333

Slim chance wins:
Roy 12, Belfour 9, Cujo 6, Hasek 5, Brodeur 1

Dominik Hasek emerges as the leader here, winning nearly two out of every three games that the Sabres were severely outshot in. Curtis Joseph also shows a clear ability to steal games. Twenty-one percent of his career playoff wins were stolen, the highest of any of the candidates. Patrick Roy has also won a large number of games for his team over the course of his illustrious playoff career.

It is very clearly revealed here how heavily Brodeur has been shielded by the Devils defence. Even taking that into account, however, he has simply not been very effective at stealing games. Only 3% of his career playoff victories were stolen wins. Even though he has mostly played well in the playoffs, he has never been leaned upon to win games on his own, and he hasn't been successful when asked to do so. It appears that his "game-stealing" reputation is hype and not reality.

Overall Game-Stealing Ability:
1. Hasek
2. Cujo
3. Roy
4. Belfour
5. Brodeur