Previewing the second-round series between the Milwaukee Bucks and Boston Celtics with shot charts, assist maps, offensive style charts and expected win probabilities.
Shot charts
The Milwaukee Bucks took no time in dispatching the Detroit Pistons, who were without a healthy Blake Griffin for the entirety of the series. As evidenced in the point per shot charts (green equals better in playoffs compared to the regular season), the Bucks were generally more efficient from 3 and at the rim than they were in the regular season – a frightening prospect for a team that had the best record. For the series, they shot 37 percent from three on 34 attempts per game and also averaged 55 points in the paint per game. Their interior defense was strong as well, holding the Pistons to 40 points in the paint per game. Both offensive and defensive points in paint numbers were slightly better than regular season averages. Giannis Antetokounmpo was incredible as well, with a 64 true shooting percent and 31 percent usage over about 33 minutes a game. In addition, Eric Bledsoe provided substantial self-created offensive punch to pair with his usual tremendous defense, with over 60 percent of his makes coming as unassisted with a true shooting of 58 percent on 22 percent usage.
Based on the final box scores, it appeared that the Boston Celtics rolled the Indiana Pacers with stifling defense and enough offense to get the job done. However, based on data from Krisha Narsu, a Nylon Calculus contributor, the Celtics only spent approximately 48 percent of the series with the lead. As a comparison, the least dominant other winning Eastern Conference team lead 62 percent of their series. Looking at the points per shot differential charts, the Celtics won this series with their defense, holding Indiana below season efficiency averages essentially everywhere on the court, with a minus-7 percentage point difference in true shooting to their regular season mark. Of note, the Celtics played at a pace of 96 possessions per game, whereas their upcoming opponent, the Milwaukee Bucks, was the second-fastest team in the regular season, at slightly over 103 possessions per game. How the Celtics play speeds up, or how they force Giannis Antetokounmpo et al. to slow down will be a major factor in how the series turns out.
— Andrew Patton (@anpatt7)
Offensive style chart
These charts are not meant to evaluate whether an offense is good or bad. They are designed to help illustrate how teams go about the goal of trying to put the ball in the basket. Each team’s offense is evaluated on four stylistic spectrums.
Ball movement is measured with the average touch time for each team, from the NBA’s player tracking statistics. A lower average touch time means the ball is moving from player to player more quickly.
Player movement is measured with a combination of different NBA.com tracking statistics and works out to average distance traveled per 24 seconds of offensive possession.
Pace is measured with the average length of an offensive possession from Inpredictable, a more accurate representation for how quickly a team is working than traditional pace.
Shot selection is measured with MoreyBall percentage — in this case the percentage of a team’s true shooting opportunities that came at the rim, from the free throw line, or on a 3-pointer. It’s a generalized measure but captures something about how much each team hews to the shots that are, on average, the most efficient.
— Ian Levy (@HickoryHigh)
Assist maps: Kyrie Irving
Kyrie Irving asked out of Cleveland because he wanted to be The Man. He was looking for a new professional challenge; a chance to captain his own team. Irving is getting his opportunity to run the show in Boston where he has been the leader in time of possession (5.5 minutes) and assists (6.9) per game this year, with an even bigger share of the playmaking responsibilities on his shoulders in the first round against Indiana (7.5 minutes of ball possession and 7.8 assists per game).
And, all things considered, the results have been mostly pretty positive. Irving is having a successful year; he was an All-Star and will likely earn All-NBA honors, too. His team — despite occasional struggles — is basically right where it wants to be, in the second round of the playoffs with a chance to return to the Eastern Conference Finals.
Yet, some nagging questions linger. Why wasn’t a healthier Irving able to help the Celtics improve on their record from last year? Why do the Celtics play just as well (at least in terms of net- and offensive ratings) when Irving is OUT of the lineup as they do when he is ON the court? And why is it that having Irving around doesn’t seem to improve the quality of his teammates’ shots very much? Perhaps we can find some clues in his assist chart.
With his unreal handle and nifty finishing, Irving is adept at getting to the basket. Among the 50 players who drive to the hoop most frequently (10+ drives per game, according to the NBA’s tracking data), Irving ranks 7th in points scored per drive (0.67) right alongside some of the games most dominant playmakers: James Harden (0.71), Giannis Antetokounmpo (0.71), and LeBron James (0.68). But — perhaps because he finds it so easy to score himself — Irving doesn’t usually penetrate with the intention to set up his teammates. Among those 50 most-frequent drivers, Irving was the 13th-least likely to finish one of his drives with a pass (35%). As a result, fewer of his assists tend to be converted at the rim (36 percent per PBPstats.com) compared to other primary ball handlers (Irving’s at-rim assist frequency ranks 9th-lowest in the group of 50). Likewise, a relatively small fraction (8 percent) of Irving’s assists are kicked out for corner 3s (12-lowest rate in the group). We see the evidence for some of these tendencies on Irving’s assist charts, where there are not very many passes originating inside the paint.
Against Milwaukee, Irving will be asked to do more than just distribute the ball around the perimeter. The Bucks had the best defense in the league this year — holding opponents to 104.9 points per 100 possessions — and they have improved on that mark in the playoffs (96.8 DRTG vs. Detroit). If Boston is to crack that defense and win the series, Irving will need to help his teammates score by putting them in advantageous situations where they can capitalize on his skill and creativity. Put simply, he will need to be The Man. It should be a good challenge, one I’m sure Irving will relish.
— Todd Whitehead (@CrumpledJumper)
Win probabilities
To project the series, I am using my in-season game projection model. The model is trained off historical game data and accounts for rest, travel, team strength, and matchup. Since I began using the model to predict outcomes, I have been able to correctly identify the winner in about 70 percent of games.
The Bucks come into the series as strong favorites, winning in 89 percent of the 10,000 simulations. The average length of the series was 5.4 games, with the Bucks given over a 22 percent chance to sweep the series. The unknown availability of Marcus Smart for the series hurts the Celtics here. With both teams coming off sweeps in the first round, they will both have plenty of time to prepare for the other. The model seems a little too low on the Celtics’ chances, but the Bucks were statistically the strongest team in the NBA this season and have as much high-level depth as anyone. Expect this to be an interesting series of adjustments, but the Bucks should be favorites to move on to the Eastern Conference Finals.
— Jacob Goldstein (@JacobEGoldstein)