It’s the half way mark of the NBA season and time to check-in on some high level metrics across the NBA, namely “eFG% Advantage”.
If you’ve never heard of such a data point, don’t worry; we wrote about the subject earlier this season. In short, it’s the difference between a team’s efficiency and that of their opponent.
Historically, it’s correlated well (albeit with some variance) to season long win rate (i.e. the better you shoot than your opponent all season, the more games you win).
History— Adam Bushman (@adam_bushman) December 28, 2021
There's a relationship between eFG% advantage and regular season winning rate.
Below is a plot of every team's eFG% adv and win rate since 1996-97! A simple linear model explains approximately 74% of the variance (adj R^2)
Translation: it's a real good predictor
The Utah Jazz and Golden State Warriors have, for the majority of the season, been oscillating for the #1 spot. Until recently, Utah had found themselves free from health and safety protocols, which always gave cause for pause when evaluating their metrics.
However, with a number of players having passed (and currently stuck) in protocols, we have a better outlook on the league with that final variable ceasing to be an outlier.
Refer to the below graph for how teams are faring throughout the league in eFG% advantage:
You’ll notice the Jazz and Warriors are, again, 1-2 respectively, hovering around the +5.0% mark (translation: on average this year UTA and GSW are shooting 5% better than their opponent in eFG).
What does this mean for a season? Historically, team’s that have such a margin over their opponent end up winning 65-75% of their games, or put in terms of wins, end up with a season win total of 54-61; talk about a special season!
A nice component of this analysis is our ability to filter opponents based on a certain attribute, such as above .500 teams. Let’s take a look at where the Jazz rank through 43 games:
Now this is a much different look around the NBA, with more than half the league performing poorly (on average) against above 0.500 teams! There’s a pretty clear top tier via this perspective: GSW, PHX, and UTA, the current top 3 in the West.
For what it’s worth, here’s how certain evaluators are predicting the West to finish:
FiveThirtyEight: #1-PHX (59 wins), #2-UTA (55 wins), #3-GSW (54 wins)
Basketball Reference: #1-PHX (60 wins), #2-GSW (59 wins), #3-UTA (55 wins)
Basketball Reference: #1-PHX (56 wins), #2-GSW (56 wins), #3-UTA (54 wins)
Phoenix is beginning to separate in the standings as Utah is entering the tough portion of their schedule, where Utah has one of the 5 toughest schedules remaining.
Now is the time to show the league what Utah’s made of. Put aside the internal riffs and trade rumors, and focus on being the best team possible for the upcoming games.
Last night’s win over the Nuggets was a massive win for the Jazz, whose recent skid with half the team in protocols has made, predictably, a sizeable dent in the standings and Utah’s interest in ascending to the #1 spot.
The look to keep up that energy as they take on Los Angeles Lakers tonight in California. Looming at the end of the week is a brutal 4 game stretch of the Golden State Warriors, Phoenix Suns, Phoenix Suns, and Memphis Grizzlies, 3 of which are on the road.
It’s time to buckle up!