Shooting Variation
Expectation
If a team scores on 8.0% of their shots and takes 1800 shots, they generally will not score exactly 144 goals. It's like flipping a coin. Flip a coin 100 times and you might get heads 55 times instead of 50 times. The expected range of goals scored is easy to calculate as is the expected range of observed shooting percentages. Here the expected range of goals scored (the 95% confidence interval) is 122 to 166. The expected range of observed shooting percentage is 6.77% to 9.22%. If you accumulate 5 seasons, the range narrows to 7.44% to 8.55%
I pulled the 5v5 shooting data from David Johnson's site Hockeyanalytics.com from 2007-08 through 2011-12. I left out last year's short season.
Cumulative data
Team |
GF |
SF |
SF% |
Pittsburgh |
804 |
9223 |
0.0872 |
Vancouver |
752 |
8833 |
0.0851 |
Dallas |
715 |
8524 |
0.0839 |
Washington |
796 |
9576 |
0.0831 |
Philadelphia |
754 |
9117 |
0.0827 |
Edmonton |
692 |
8398 |
0.0824 |
Tampa Bay |
719 |
8785 |
0.0818 |
Buffalo |
772 |
9462 |
0.0816 |
Chicago |
801 |
9834 |
0.0815 |
Winnipeg |
721 |
8852 |
0.0815 |
Toronto |
757 |
9309 |
0.0813 |
Calgary |
729 |
9000 |
0.0810 |
Boston |
785 |
9777 |
0.0803 |
Nashville |
729 |
9090 |
0.0802 |
St. Louis |
705 |
8840 |
0.0798 |
Anaheim |
670 |
8407 |
0.0797 |
Montreal |
686 |
8716 |
0.0787 |
Colorado |
710 |
9050 |
0.0785 |
Detroit |
798 |
10237 |
0.0780 |
Ottawa |
714 |
9211 |
0.0775 |
Minnesota |
613 |
8012 |
0.0765 |
Carolina |
707 |
9271 |
0.0763 |
Phoenix |
703 |
9238 |
0.0761 |
NY Rangers |
694 |
9181 |
0.0756 |
Columbus |
661 |
8770 |
0.0754 |
Los Angeles |
654 |
8782 |
0.0745 |
Florida |
684 |
9213 |
0.0742 |
San Jose |
720 |
9721 |
0.0741 |
New Jersey |
659 |
8997 |
0.0732 |
NY Islanders |
644 |
9003 |
0.0715 |
So, over the last 5 years combined, Pittsburgh, at 8.7%, has been able to shoot at a rate statistically significantly better than 8.0%. Florida, San Jose, New Jersey, and the Islanders have managed to shoot at a rate statistically significantly worse than 8.0%
Rank Order
I ranked the teams from 1 to 30 each year, and added up the ranks. If the Blues were the best team each year, they would have a score of 5. If they were the worst team each year, they would have a score of 150. An average team would have a score of 77 or 78. The standard deviation is 19.35 so a 95% confidence interval is 40 to 115.
Team |
rank2007 |
rank2008 |
rank2009 |
rank2010 |
rank2011 |
ranktot |
Pittsburgh |
2 |
1 |
6 |
22 |
3 |
34 |
Vancouver |
19 |
2 |
2 |
8 |
11 |
42 |
Dallas |
7 |
5 |
10 |
1 |
21 |
44 |
Chicago |
5 |
23 |
7 |
10 |
11 |
56 |
Edmonton |
2 |
6 |
11 |
23 |
17 |
59 |
Philadelphia |
18 |
8 |
26 |
2 |
5 |
59 |
Buffalo |
2 |
14 |
17 |
19 |
13 |
65 |
Toronto |
15 |
11 |
27 |
5 |
7 |
65 |
St. Louis |
10 |
16 |
13 |
4 |
24 |
67 |
Winnipeg |
13 |
4 |
3 |
27 |
20 |
67 |
Boston |
27 |
3 |
30 |
6 |
2 |
68 |
Tampa Bay |
17 |
17 |
19 |
15 |
1 |
69 |
Calgary |
9 |
11 |
28 |
3 |
19 |
70 |
Nashville |
12 |
19 |
24 |
9 |
6 |
70 |
Washington |
20 |
19 |
1 |
21 |
10 |
71 |
Anaheim |
23 |
10 |
8 |
17 |
16 |
74 |
Colorado |
6 |
25 |
4 |
14 |
26 |
75 |
Montreal |
8 |
13 |
25 |
28 |
9 |
83 |
Detroit |
22 |
15 |
29 |
16 |
4 |
86 |
Ottawa |
1 |
24 |
16 |
29 |
18 |
88 |
Los Angeles |
14 |
26 |
12 |
7 |
30 |
89 |
Minnesota |
11 |
22 |
9 |
18 |
29 |
89 |
NY Rangers |
25 |
30 |
14 |
13 |
8 |
90 |
Carolina |
16 |
27 |
15 |
10 |
23 |
91 |
Phoenix |
29 |
18 |
21 |
12 |
14 |
94 |
Columbus |
30 |
7 |
20 |
24 |
22 |
103 |
Florida |
24 |
9 |
18 |
26 |
28 |
105 |
San Jose |
21 |
29 |
5 |
25 |
26 |
106 |
New Jersey |
26 |
21 |
23 |
30 |
14 |
114 |
NY Islanders |
28 |
28 |
22 |
20 |
25 |
123 |
Pittsburgh manages to be better than average and the Islanders worse than average.