Predicting NBA Champions & Using Advanced Stats For NBA Championship Futures

With the NBA playoffs around the corner, the top teams are jockeying for home court down the stretch. However, seeding is not the best predictor of playoff success. Is there a more accurate method to determine why certain teams made deep runs? I looked back at the last four playoff brackets (2018-2021) to examine the advanced stats. Two advanced stats that are extremely favorable towards success are net effective field goal percentage ( Net eFG%) and Net Rating. A positive Net eFG% and Net Rating is a good thing, while negative of the stats is a cause for concern. 

Per Basketball Reference, eFG% “adjusts for the fact that a 3-point field goal is worth one more point than a 2-point field goal. For example, suppose Player A goes 4 for 10 with 2 threes, while Player B goes 5 for 10 with 0 threes. Each player would have 10 points from field goals, and thus would have the same effective field goal percentage (50%).”

eFG% = (FG+(0.5*3PT)) / FGA.

Net eFG% is the difference between eFG% and opponent eFG%. Net eFG% = eFG% – opponent eFG%. 

Net Rating is the difference between points scored per 100 possessions and points allowed per 100 possessions. Net Rating = Offensive Rating – Defensive Rating. 

Every 2022 NBA Team 

Why are both stats important? Net eFG% indicates the shot quality of a team in conjunction with their overall efficiency. Teams with a high Net eFG% have a tremendous advantage because their shot profile is more beneficial in the long run. They are forcing opponents into tougher field goal attempts while taking efficient ones themselves. Net Rating takes a broad view of a team and measures their overall success as a whole. It’s adjusted for pace and standardized since it is per 100 possessions. Net Rating doesn’t delve into the minute details of a team; it measures whether a team is successful in scoring more points than the opponent when all else is equal. 

2022 Regular Season: Net eFG% vs Net Rating

*All stats from NBA.com

*Stats from 2/27/22

When looking at all 30 teams, only 12 are positive in both Net eFG% and Net Rating (They are bolded in the chart – Suns, Warriors, Jazz, Celtics, Cavaliers, Heat, Mavericks, Bucks, Nuggets, Bulls, 76ers, Hawks). The only team positive in both that is below the 6th seed in either conference is the Atlanta Hawks, who are currently the 10th seed. The Suns, Warriors, and Jazz are the three favorites here, with the Celtics close on their heels. Notable teams outside of this desirable quadrant are the Grizzlies, Lakers, Clippers, Nets, Hornets, Raptors, and Timberwolves. However, the Nets and Clippers injuries must be considered here.

2018-2021 Teams Who At Least Made The Conference Finals

Now that we have a picture of where teams currently sit, let’s compare them to recent teams who made deep runs. All four teams who made the conference finals are represented, spanning from the 2018 playoffs to the 2021 playoffs. The 8 teams in black font lost in the Conference Finals, while the 8 teams in green font went on to play in the NBA Finals.

Conference Finals Teams 2018-2021: Net eFG% vs Net Rating

As you can see, every team was positive in both metrics. There are three clumps of teams here: Cinderellas, Normal, and Great. The Cinderellas are the six teams in the bottom left (Nuggets, Cavaliers, Hawks, Heat, Celtics, Trail Blazers) who measure low relative to other teams who had a Conference Finals berth. They either played above their talent level or had outside factors that explain why those teams bucked the trend and advanced beyond the 2nd Round. The 2018 Cavaliers should not have made the Finals, but they had one of the greatest players of all time – LeBron James – carry them there. In the 2018 playoffs, LeBron led all players in scoring at 34 PPG while also producing 9.1 RPG and 9.0 APG. The Cavaliers as a team were not great, but LeBron’s greatness prevailed. The 2020 Heat, meanwhile, made their run in the NBA Bubble. Whether that actually had an effect or not is debatable, but there is no ignoring the fact that teams were playing in unorthodox conditions.

The Normal teams were great teams deserving of their success. The Suns, Bucks, Raptors, and Lakers ran through the regular season and dominated the playoffs. The Clippers lost Kawhi to a torn ACL, and the Celtics lost in the Bubble. Meanwhile, the Great teams were extraordinary. The Durant-Warriors and Rockets were so lethal from three that their eFG% blew away their opponents. Both defenses were excellent, capable of switching. The Bucks were eager to prove their role as a titan in the East through Giannis’ two-way play.

2018-2021 Conference Finalists Mean and Median

Overall, 5 of the 8 teams in the Finals had a Net eFG% at 3 or above. 7 of the 8 teams had a Net eFG% of at least 2.4 (besides the one with prime LeBron carrying them). In terms of Net Rating, every team had a Net Rating of at least 5 except for the 2018 Cavaliers and 2020 Heat. A decent benchmark for contenders is a Net eFG% of 3 and a Net Rating of 5.

Top 10 Seeds in East and West vs 2018-2021 Conference Finalists

Here is a comparison between the current top 10 seeds in each conference vs the Conference Finalists from 2018-2021. Teams in green went to the Finals, and teams in red lost in the Conference Finals. Teams in black are current 2022 teams. 

2022 Top 10 East & West Seeds vs 2018-2021 Conference Finals Teams: Net eFG% vs Net Rating

This year’s Suns, Warriors, and Jazz are not surprising given their usual excellent play. The Celtics and Cavaliers, though, are above teams like the Heat, Bucks, and Bulls. The 76ers will likely improve considerably because of the Harden trade. The Celtics have played superb defense and roster elite shot makers. The Cavaliers impose their will on defense while getting offensive production from Garland and LeVert. Both teams may outperform expectations in the playoffs and go on a deep run. The Grizzlies are surprisingly not in the desirable quadrant, which doesn’t bode well for their chances based on recent history. LeBron will need a miracle to get the Lakers to the Conference Finals, and this graph agrees with that assessment. The only 2022 teams that hit the benchmark (3 eFG% and 5 Net Rating) are the Suns, Jazz, Warriors, and Celtics. The Cavaliers are close at 2.8 Net eFG% and 4.1 Net Rating, but they fall short of the goal. 

After seeing where teams today stack up against recent successful teams, it’s clear that being positive in both metrics is a great sign of things to come. However, it doesn’t mean the top teams are destined for success, as unpredictable things constantly happen.

2022 NBA Championship Futures

I am currently a junior at University of Pennsylvania majoring in Psychology. I have spent the last few years working with various UPenn athletics teams and contributing to the UPenn Sports Analytics Group. My primary interests reside in NBA, NFL, and College Football.

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