Wilson: Quality starts and the postseason

Goaltending in the playoffs is a huge part of a team’s success or lack thereof.  It is a position that can ruin well-built teams or prop up poorly managed clubs.  Most teams just want consistency from the position and in reality that is usually all it takes to win games with a good team.

Today I wanted to take a look at Rob Vollman’s Quality Start stat and dive into how it has impacted a team’s ability to win playoff series.  I have combed through every playoff game since the 2005-06 season and have tallied how many quality starts each team has received and what their winning percentage is during this time frame in the playoffs.

What is a Quality Start?

In order to record a Quality Start, the starting goalie must stop at least a league average number of shots (typically 91.3% prior to 2009-10, and 91.7% since), or play at least as well as a replacement level goalie (88.5%) while allowing two goals or fewer.

What makes for a good Quality Starts percentage?

Per Rob Vollman:

Obviously, a quality start percentage (QS%) below 50% is quite poor, anything over 60% will be among the league leaders, and the average for an NHL regular is 53.4%.

I have limited the data to only include teams who played in 20 playoff games or more during this sample size, this excludes Columbus (10), Florida (7), and Toronto (7).

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With an r2 of .20 we see that Quality Starts can explain 20% of a team’s playoff success.  Given the fact there are so many moving parts in a hockey game finding something that you can attribute 20% of a team’s potential success seems like a good find.  Quality Starts won’t explain the whole picture, but it is rough measure than can be useful when trying to analyze the goaltender position.

We see that some teams like Detroit and Boston have a stronger positive correlation with Quality Starts and their winning percentage, while Pittsburgh and Chicago have a weaker correlation.

There are exceptions to the rule.  Here are a few teams who have seen their playoff winning percentages way lower than their Quality Starts percentage

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For a few of these teams (Arizona, Calgary, and Nashville) we can see that their quality goaltending was wasted by having poor possession.  Possession is still the biggest factor that drives success in the modern day NHL.

Minnesota and St. Louis have been on the unfortunate end of the luck spectrum.  They have had quality goaltending as well as quality possession and have not had any tangible results to show for it.  St. Louis has played well, but running into LA twice and Chicago once in the first round isn’t exactly ideal for winning playoff series.

On the flip side only three teams since the 2005-06 lockout have had a higher winning percentage than they do a Quality Starts percentage.

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Chicago and Pittsburgh are able to find varying degrees of success because they are consistently above the 50% barrier in puck possession.  However, one could argue that the Penguins and their sub 50% quality starts percentage is the main reason why they have underachieved in the playoffs in recent memory.  Pittsburgh is also only one of three teams since the lockout to post a sub 50% Quality Saves percentage.  They are the only one of those three teams to have a winning percentage above 50%.

The Flyers have probably won more games in the playoffs than what their bad goaltending should have allowed for, combine that with the poor possession and it is no wonder why they win less than 50% of their playoff games.

Here are some other facts I came across while collecting this data

Quality Starts by round:

Round 1 (453/828) 54.7%

Round 2 (241/414) 58.21%

Round 3 (107/194) 55.15%

Round 4 (65/110) 59.01%

No surprise that Round 1 has the fewest and Round 4 has the most frequent.

Record of teams with more Quality Starts than their opponent in a playoff series: 84-13

Record of teams with a Quality Start in each game of an individual playoff series: 14-0

Record of teams with no Quality Starts in an individual playoff series: 0-12.

Here is the raw data for each playoff team since the lockout:

 

Team         QS         GP       QS%       Wins       GP            Winning %
ARI

18

27

67%

12

27

44%

ANA

47

82

57%

46

82

56%

BOS

65

97

67%

57

97

59%

BUF

27

47

57%

25

47

53%

CAL

14

26

54%

10

26

38%

CAR

24

43

56%

24

43

56%

CHI

48

89

54%

53

89

60%

COL

15

32

47%

13

32

41%

CBJ

2

10

20%

2

10

20%

DAL

21

36

58%

16

36

44%

DET

73

111

66%

64

111

58%

EDM

16

24

67%

15

24

63%

FLA

5

7

71%

3

7

43%

LA

51

76

67%

45

76

59%

MIN

15

29

52%

10

29

34%

MTL

36

70

51%

29

70

41%

NAS

25

44

57%

17

44

39%

NJ

33

61

54%

27

61

44%

NYI

2

11

18%

3

11

27%

NYR

56

93

60%

43

93

46%

OTT

29

57

51%

28

57

49%

PHI

34

81

42%

39

81

48%

PIT

49

103

48%

58

103

56%

SJ

50

97

52%

48

97

49%

STL

13

25

52%

8

25

32%

TB

17

33

52%

14

33

42%

TOR

3

7

43%

3

7

43%

VAN

38

68

56%

33

68

49%

WAS

34

58

59%

27

58

47%

WPG

1

4

25%

0

4

0%

 

 

 

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