There are hundreds of methodologies to try and determine how good an NBA team is. All your major Sports Media sites have their own way of doing so; now TPL does too. PPI stands for the PaintedPowerIndex and it rates teams based off a variety of factors. The biggest factors are strength of schedule as well as margin of victory. It also incorporates home vs. away splits, as obviously winning on the road is much harder than winning at home (and gives a less bias look at a team).
Strength of Schedule
One of the most vital pieces of information when rating a team is who they have played. This doesn’t just mean who a team has played, but also who the teams they play have played. The latter is called opponents’ strength of schedule. These two factors are combined to give us a number that represents the average win percentage of your schedule. This accounts for 50% of the teams PPI rating.
Margin of Victory
Just as who you beat is important, it’s also important to note by how much you beat them. Margin of victory isn’t the best stat by itself because teams have off nights, injuries, etc., but it does give a picture of “how” good a team is compared to other teams. PPI includes margin of victory by using the Pythagorean win percent estimation and applying that to a home/away split rating to come up with a team’s Win Percent Factor. This is the other 50% of PPI.
Home vs. Away Splits
Winning on the road is harder than winning at home, obviously. Home teams in the NBA this year have won 56.5% of the time. Because of the discrepancy of a home versus an away win, PPI values road wins higher than home wins and also treats a home loss worse than a road loss. The factor by which these splits are multiplied tries to give a more neutral approach to a team’s record. While home and away isn’t a stand alone factor in PPI, it is a massive factor when determining a team’s Win Percent Factor, as noted above.
So What’s This Mean?
Milwaukee, not surprisingly, is the best team in the NBA. Despite facing the easiest schedule in the league so far, the Bucks 33-6 record and 11.8 margin vault them past the Lakers. What PPI does show is that the NBA is a two-team league right now, as the Bucks and Lakers are head and shoulders above the rest of the league.
The Mavericks are a surprise at three, but this is because of a top ten hardest schedule, a 7.2 margin (third best in the league), and also because Dallas is great on the road. Their 12 road wins are tied with the Rockets for third most in the league. The 76ers check in at eleventh, which is disappointing considering preseason expectations. Their ninth best margin and sixth hardest schedule are definitely factors that push this team up the ratings, but their inability to win on the road is what keeps them from being a top-tier team.
The three strength of schedule columns are broken down as such: Current SoS, Week SoS (a team’s strength of schedule for the upcoming week), and Future SoS (a team’s remaining schedule strength). The Sixers face an average schedule this upcoming week (1/10 through 1/17) but will see a major decrease in difficulty to end the year. Hopefully that will be enough to push the Sixers to a top 4-seed so they get home court in at least one round.
Projected draft order results are based off of PPI’s win/loss predictions and do not incorporate any trades or conditions placed on picks.
Finally, PPI is able to predict a team’s final record using both current records and a prognostication based off a team’s future SoS. The Bucks have a 10-game predicted lead over the Heat for the 1-seed in the East, but after that there are four teams within 5-projected games of each other. There could be a ton of variability to close the year for the two through five seeds with the Heat and Celtics currently at the top. As of now, the eight playoff teams seem to be set with the Pistons, Bulls, and Hornets over six projected games out of the race.
In the West, the Lakers hold a 9-game projected lead over the Clippers for the 1-seed, but like the East, seeds two through five are separated by one game. The Rockets, Nuggets, and Jazz are all predicted to win 55 games, so let the wacky tie-breaker procedures commence.
I will be updating PPI weekly throughout the NBA season. As this is a first time analysis using PPI, it will be interesting to see how accurate these results are and if there are other applicable uses for PPI (i.e. betting).