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Save Percentage On Ice/Off Ice

I opened another can of worms.


In an earlier post, Scott Reynolds pointed out the discrepancy between on ice save percentage and off ice save percentage for Smid, Fistric, Weaver, and Giordano. So I computed it, and sure enough, Smid's on ice save percentage falls outside the 95% CI established by his off ice save percentage. Same for Weaver. Same for Fistric. Same for Giordano. Uh-oh!

So I went through and calculated Z-statistics for everybody's on ice save percentage relative to their off ice number. Of the 879 players in the 2009 table, 61 had a Z-statistic above +2.0 and 89 had a Z-statistic below -2.0. This includes Fistric at +5.21 and 13 players at -4.0 or less. Jack Johnson is at -7.61. So if save percentages are the same on ice as off ice, there are some incredibly unlikely outcomes.


In 2008, same thing. 886 players. 55 above +2.0. 81 below -2.0 7 below -4.0 Marty Reasoner at +4.21 Alex Henry at -7.22.


2007 has 852 players. 67 above +2.0 86 below -2.0. 9 below -4.0 V. Kozlov at +4.51 Michael Nylander at -5.92.


Then I looked at whether players differ statistically over the 3 years.


LinearModel.1 <- lm(Z ~ NAME, data=zstat)



Analysis of Variance Table

Response: Z

           Df Sum Sq Mean Sq F value Pr(>F)

NAME      1184 3336.8 2.8182 1.4486 1.368e-11 ***

Residuals 1406 2735.3 1.9455


52 players are significantly better than average, including Fistric, Weaver, and Smid, Giordano is close. 4 are worse than average: Jack Johnson, Brad Richards, Derek Smith, and Alex Henry. I put the table of coefficients at


So it looks like (I'm probably going to get hate mail for this) some players may well influence save percentage. The effect seems to persist over the 3 years for which I have data.