The conference quarter finals are coming to a close as the Bucks, Raptors, Celtics, Heat, Lakers, Clippers, Nuggets, and Rockets have advanced to the conference semi finals. In this article, I will give the updated round by round probabilities for each of the 8 remaining NBA teams, and I will preview the four conference semi final matchups.
Model Performance
In round 1 of the NBA Playoffs, my model had the Bucks winning in 4, the Raptors winning in 5, the Celtics winning in 6, the Heat in 5, the Lakers in 5, the Clippers in 6, the Nuggets in 6 or 7 (it was a tie between the two), and the Rockets in 5. Thus far, the model has gone 8 for 8 on predictions while predicting three series (Lakers, Clippers, Nuggets) exactly. I’d say those are pretty good results and increase the credibility of my model, other than the huge Bucks bias.
Updated Probabilities
Using the same logistic regression that I used at the beginning of the playoffs, I found the chances of each remaining team beating each other. However, I realized that I did not account for the fact the the stats from the bubble may be more representative of each team’s play in the playoffs than the regular season as a whole. Therefore, when I found the net rating, shooting advantage, and best player BPM for each of the remaining teams, I weighted the bubble stats slightly more and also weighted the stats from the first round of the playoffs the same way. The weights I chose were 75% for the regular season as a whole, 12.5% for the bubble stats, and 12.5% for the first round stats. How this works is that if a team had a net rating of +5.0 in the regular season, +3.0 in the bubble, and +2.0 in the first round, their weighted net rating would be 0.75*5.0 + 0.125*3.0 + 0.125*2 which is about +4.38.
These adjustments changed the championship and round by round odds significantly. Teams such as the Celtics and Clippers who have done well in the bubble have had their chances boosted, while teams that have done worse in the bubble than the regular season, like the Lakers and Bucks, have had their chances decreased. The new probabilities are shown below.
The title favorites according to the model are still the Bucks. The Bucks have an experienced roster, the best net rating, the best shooting advantage, and the best player according to BPM, meaning the model will favor them in any series against any team. The Clippers have the best chance in the West, with the new weights on bubble performance helping them while hurting the Lakers. Of the teams in the conference semi finals, the Nuggets look like the odd one out, being the only team with a chance lower than 1%.
Note: All the probabilities shown above are calculated as if all the second round matchups started at the same time (Celtics-Raptors and Bucks-Heat games have not been taken into account). To see updated championship probabilities, visit the daily updated playoff probabilities page.
Matchup Previews
East: 1 Bucks vs 5 Heat
Series win probability: MIL 89.7%
Expected Result: MIL in 5
Game 7 Probability: 16.5%
Key Player: Bam Adebayo
Both the Bucks and the Heat won easily in the first round and will play in the second round. This is a very interesting matchup. The Heat offense plays exactly the way they need to in order to beat the Bucks top ranked defense. The Heat don’t take shots at the rim as often as most teams do, opting to take more 3 pointers. This is good for them since the Bucks allow many 3 point attempts while trying to prevent shots from the rim. Even worse for the Bucks, the Heat make threes at a high rate and their shooters cannot be left open: the Heat have a 0.573 eFG% (1.146 pts per shot) when they have an open shot. For these reasons, the probability the Bucks win this series is likely lower than the model predicts.
Unfortunately, figuring out the player matchups for this series is difficult as Jimmy Butler only played in 1 of their 3 regular season tilts. However, one interesting matchup is Bam Adebayo against Brook Lopez as Adebayo scores just 0.663 points per possession against him. On the defensive end, Adebayo is the key to stopping Giannis, as Giannis has 0.927 points per possession when guarded by him. If Adebayo can get better against Brook Lopez while still containing Giannis, the Heat will have a good chance to win. Although it is an interesting matchup, I expect the Bucks to win in 5 or 6 games.
(This prediction isn’t looking good right now but I have to stick with it)
Note: To see updated probabilities, visit the daily updated playoff probabilities page.
East: 2 Raptors vs 3 Celtics
Series win probability: BOS 58.4%
Expected Result: BOS in 6
Game 7 Probability: 30.7%
Key Player: Jaylen Brown
After the Celtics embarrassed the 76ers in the first round, they are set to take on the Raptors in the second round. Both teams were dominant in the first round, but the Celtics were better (+19.8 net rating against the 76ers) and are the favorites of the series. The Celtics have the better offense and are better at creating their own shot, with a 0.506 eFG% when taking a shot after 3 or more dribbles.
This matchup is just bad for the Raptors, as their best player in the first round, Fred VanVleet, scores just 0.582 points per possession when guarded by Kemba Walker. Jaylen Brown has also done well guarding Pascal Siakam (0.958 PPP). If the Raptors want to win, they will have to play great defense on Tatum (0.846 PPP when guarded by Ibaka), Walker (0.84 PPP when guarded by VanVleet), and Brown (1.094 PPP when guarded by Siakam) as they did in the regular season. Jaylen Brown is the key to the series for the Celtics. If he plays well, the Celtics will have 3 offensive stars which will likely result in a mismatch somewhere, but if he doesn’t, the Raptors can focus on Walker and Tatum more and slow the Celtics offense.
Note: To see updated probabilities, visit the daily updated playoff probabilities page.
West: 1 Lakers vs 4 Rockets
Series win probability: LAL 50.4%
Expected Result: LAL in 7
Game 7 Probability: 31.2%
Key Player: Anthony Davis
The Lakers beat the Trail Blazers in 5 games, just the model predicted, in the first round while the Rockets won in a close series against the Thunder. The main reason for the Rockets’ difficulty with the Thunder in round 1 was Lu Dort’s defense on James Harden, holding Harden to just 1.007 (compared to a season average of 1.252) points per possession. The Lakers will have to hope Danny Green can do just as well guarding Harden, as Harden had just 0.87 points per possession against Green in their regular season matchups, albeit with a small sample size of only 12.6 possessions.
However, the Lakers will also have to guard Russell Westbrook, who has destroyed them when they have played this year (averaged 38 points per game with 1.30 points per possession). If Houston’s role players step up, then the Lakers will have their hands full in the second round. Their recipe for winning should be to attack the Rockets’ biggest weakness: size. The Lakers will need to dominate on the offensive glass and get lots of easy shots close to the basket. The key to accomplishing these tasks is Anthony Davis, who will have to perform consistently well on getting to the basket, getting offensive rebounds, and defending both the paint and perimeter.
West: 2 Clippers vs 3 Nuggets
Series win probability: LAC 88.6%
Expected Result: LAC in 5
Game 7 Probability: 17.5%
Key Player: Nikola Jokic
The Nuggets came back from down 3-1 against the Jazz, but now they have to face off against currently the best team in the Western conference in the Clippers. Since their offense was on fire, the more pressing problem for Denver comes with their defense. The Nuggets allowed 127.6 points per 100 possessions against the Jazz through the first six games; for reference, the worst defensive team in the regular season (the Wizards) allowed 115.5 points per 100 possessions. The problem the Nuggets will have to solve is Jokic’s defense. He has not been good defensively, allowing 1.368 points per possession against the Jazz in the first round on 98 possessions (through 6 games). To make matters worse, Jokic has been even more of a defensive liability against the Clippers in the regular season, allowing an abysmal 1.734 points per possession on 23.6 possessions. The Nuggets will have to rely on Jerami Grant to lock up Kawhi Leonard (0.698 PPP vs Grant) while hoping that the role players hit a shooting slump.
On offense, the Nuggets will almost surely regress as Jamal Murray has a FG% of 0.585 when his expected FG% is 41.1% (Shooting Above Average = 0.174), giving him about 3.8 field goals above expected and 9.1 points above expected. These numbers are crazily high (max SAA in reg season = 0.094 | max FGAA in reg season = 1.2), meaning Murray will not be able to carry the Nuggets and giving the Clippers a very high chance of winning the series.
The second round of the NBA Playoffs has four good matchups and should be entertaining. The favorites according to the model are the Bucks, Celtics, Lakers, and Clippers. The Lakers-Rockets series looks to be the closest, as the Lakers’ chances were hurt when incorporating the bubble stats at a larger weight because of their bad play during the seeding games. The title contenders and favorites still remain the same, with the Bucks leading the pack. However, the Clippers have overtaken the Lakers for the favorites in the Western Conference and the Celtics have a reasonable chance at a finals appearance. The second round of the playoffs will be fun to watch this year.
Best Ball Stats 