Adjusting Individual Defensive Efficiency Ratings
- 751 Comment
A couple of months ago I presented individual defensive efficiency ratings for the 2008-09 regular season that I extracted from play-by-play data. In this post I will present a method for adjusting these ratings in an attempt to get a clearer picture of a player’s defensive abilities.
Adjusting the Defensive Ratings
To adjust these defensive ratings I fit a multilevel model that allows us to measure the individual offensive, individual defensive, and team defensive impacts on individual efficiency ratings. I fit this model for each of the 2006-07 through 2009-10 regular seasons, and I also fit a single model using all data from those seasons. The results of these fits can be found in the following spreadsheet:
Adjusted Individual Defensive Efficiency Ratings
In this spreadsheet you will find tabs for each of these model fits. The ratings are in terms of the player’s difference from the average defender. Standard errors are listed along with color coded confidence levels. These color codes give us an idea as to how much confidence we have in the estimate. In other words, green means we’re confident the player is not average, red means we have little confidence the player is not average, and yellow is the middle ground between the two confidence levels.
Interpreting the Ratings
To interpret these ratings, you have to think in terms of knowing the defensive player used the possession. For example, Dwight Howard’s 2009-10 rating suggests that when he uses a defensive possession the individual offensive efficiency rating of the player that used the offensive possession is 14.7 points lower than what it would be against an average defender.
It is important to note that because this model shrinks estimates to the mean, bad defenders that get little playing time will be considered average.
These ratings also adjust for the team the player plays for, as Dean Oliver shows in Basketball on Paper how some good defensive players can play on poor defensive teams. The general idea was to try and account for “Dumars-like” players while at the same time control for the idea that one individual doesn’t have complete control over how well a team does defensively.
I haven’t done anything scientific to fully study the impact of this team adjustment, but it seems to make sense after eyeballing the impact of this on players like Pau Gasol and Chris Bosh. Eyeballing something doesn’t give us a ton of confidence, so this adjustment is worth a deeper look in the future.
Players Still Underrated After Adjustment
These adjusted ratings do little to account for the fact that we don’t have a great way of giving credit to defenders when opponents make or miss shots. Guys like Shane Battier that defend the opponent’s best offensive player aren’t going to stand out in these ratings.
What Makes Sense? What Doesn’t?
I’m still trying to learn what makes a good defender, so I’d like to hear your thoughts on what ratings make sense, and which don’t. What players have reputations for being good defenders that this model isn’t estimating well?
fildena 100mg ca
order fildena 50mg sale
vidalista uses in hindi
vidalista 20 how to take
clomid pct protocol
fildena super active 100
vidalista 40 online
order sildenafil 100mg generic
buy rybelsus online
rybelsus company
rybelsus cost at walmart
can you lose weight on rybelsus
clomid for women over the counter
clomid 50 mg success
prednisone
prednisolone ophthalmic solution
motilium for constipation
motilium 10 mg
10 mg motilium
generic motilium
vardenafil pills
levitra tablets
buy celexa cheap
citadep 10 mg tablet uses
s citadep 10
citalopram
cenforce FM
cenforce 150mg
fildena over the counter
fildena 100 mg
side effects for celexa
citalopram
citalopram
celexa
vidalista hrvatska
vidalista tadalafil reviews
malegra fxt 140mg
information about malegra tablet
ivermectine arrow lab 3 mg
digiver
cenforce fm
cenforce 200 gevaarlijk
cenforce 25
cenforce 100 mg
how to take levitra
how does levitra work
buy vidalista
vidalista 60 gebruiksaanwijzing
fildena mg
fildena 100mg
priligy dapoxetine in usa
dapoxetine 30
20 mg tadalafil 60 mg priligy
dipocsitin
is vidalista 20 safe
vidalista 20 used for
vidalista 60
vidalista super active
stendra over the counter
stendra genérico preço
fertomid dosage
pregnancy fertomid 50 mg
vidalista 40
vidalista 60
buy sildenafil 100mg without prescription
fildena 100mg tablet
vidalista 20 mg price
vidalista is the generic medicine of what drug
generic vidalista
vidalista 40 side effects
buy keflex
keflex
generic xenical
xenical online
valif
levitra 20mg
order tadalafil
tadalafil 20mg coupon
buy furosemide otc
buy furosemide 100mg online
fildena 50 mg price in india
fildena 100 purple for sale
cenforce 200
order Cenforce online
centurion laboratories vidalista reviews
vidalista 40
purchase cialis online
cialis dose
seretide puff
seretide diskus 250
cenforce 50 side effects
side effects of cenforce 100
probenecid 500
probenecid tablet
isotroin 20 mg effect on periods
is isotroin accutane
cheap fildena
buy sildenafil 50mg
isotroin medicine
long term side effects of isotroin