Jody Shelley vs Ilya Kovalchuk - Who's the better shooter?

Let's go back to a familiar chart - Jody Shelley's observed shooting talent vs that of Ilya Kovalchuk:

Shelley_kovalchuk1_medium

Just a reminder: shooting talent is the amount by which a player exceeds the expected shooting percentage based on the locations he shoots from.  I've only included initial shots at even-strength in this analysis - no rebounds, no power-plays.

Looking at that chart, it seems apparent that Jody Shelley could be a better shooter than Ilya Kovalchuk.  The probability is quite low - less than 1% - but Kovalchuk has more than a 5% chance of being a net negative shooter, while Shelley has a similar probability of being a net positive shooter. 

How is that possible?  Anybody who's ever watched Kovalchuk play knows he's a slick offensive player who can pick a corner as well as anyone in the league, while Jody Shelley is the definition of 'hands of stone' - there might be several million people in the world who can shoot better than he can.  Those observations aren't wrong - they just aren't perfectly reflected in the limited number of shots taken by the two players.

So how do we resolve this?  First, consider every shooter who 200+ shots over the last five seasons and look at the mean and standard deviation of their shooting talent.  Next, we simulate a group of league-average shooters over the same number of shots.  This allows us to determine the talent and luck involved in shooting:

 

Avg Std Pct
Total 6.36 1.53
Luck 6.36 1.03 45
Talent 6.36 1.13 55

 

So we can now start with an underlying distribution for each player - with a standard deviation of 1.13% - and update it based on how the player did in the five post-lockout seasons.  We get the following distributions for Shelley's and Kovalchuk's talent:

Shelley_kovalchuk2_medium

Now we have a much different story.  When we assume an underlying shooting talent distribution, we get an entirely different story - in this case, the likelihood that Jody Shelley is a better shooter than Kovalchuk is about 1-in-10000.  And it's probably lower than that - I binned my results in a way that doesn't really give us precision beyond the fourth decimal place.  Regardless, it's clear that Kovalchuk must be a better shooter than Jody Shelley.

Here we can see Kovalchuk's observed performance versus his likely talent:

Shelley_kovalchuk3_medium

Kovalchuk's true talent level - as implied by five seasons worth of data - is approximately 10.2%, which is 3.4 standard deviations above the mean of our initial distribution.  There's a small amount of uncertainty on that z-score, so it's possible Kovalchuk is just (just!!) three standard deviations above the mean.  Either way, Kovalchuk is no worse than the second-most talented shooter in the league, and most likely the most-talented.  And there's no question that he's better than Jody Shelley.

X
Log In Sign Up

forgot?
Log In Sign Up

Please choose a new SB Nation username and password

As part of the new SB Nation launch, prior users will need to choose a permanent username, along with a new password.

Your username will be used to login to SB Nation going forward.

I already have a Vox Media account!

Verify Vox Media account

Please login to your Vox Media account. This account will be linked to your previously existing Eater account.

Please choose a new SB Nation username and password

As part of the new SB Nation launch, prior MT authors will need to choose a new username and password.

Your username will be used to login to SB Nation going forward.

Forgot password?

We'll email you a reset link.

If you signed up using a 3rd party account like Facebook or Twitter, please login with it instead.

Forgot password?

Try another email?

Almost done,

By becoming a registered user, you are also agreeing to our Terms and confirming that you have read our Privacy Policy.

Join Arctic Ice Hockey

You must be a member of Arctic Ice Hockey to participate.

We have our own Community Guidelines at Arctic Ice Hockey. You should read them.

Join Arctic Ice Hockey

You must be a member of Arctic Ice Hockey to participate.

We have our own Community Guidelines at Arctic Ice Hockey. You should read them.

Spinner.vc97ec6e

Authenticating

Great!

Choose an available username to complete sign up.

In order to provide our users with a better overall experience, we ask for more information from Facebook when using it to login so that we can learn more about our audience and provide you with the best possible experience. We do not store specific user data and the sharing of it is not required to login with Facebook.

tracking_pixel_9355_tracker