Nylon Calculus: Celtics-Cavaliers win probabilities, style, matchups and more

In a roundabout way, this is the Eastern Conference Finals match-up people expected 00 but not like this. Boston was a successful team in the regular season with Kyrie Irving and Gordon Hayward both injured. Cleveland has perennially been the post-season favorites for the Eastern Conference, but this season was a mess. How did they defy the odds and make it to the conference finals anyhow?

Well, in Cleveland’s case it was due to LeBron James’ super-human effort. You can see his stats below compared to what he did in 2009, which is the gold standard of ridiculous playoff stat-lines. He’s been remarkably similar to his younger self with only minor differences that balance out. He hasn’t shot quite as often, but he’s been slightly more efficient. He’s had more assists, but he’s created more turnovers. His production in 2009 gets the edge, partly because it was a less efficient environment and he stuck out more. But there’s one important difference.

Cleveland’s net rating (points per 100 possessions) was 11.6 when James was on the court in 2009. Now? It’s a mere 4.4. The Cavaliers got to the Conference Finals by the skin of their teeth.

Even if you believe in the power of close wins, this is not a great sign. You want that buffer that you get with a large point differential. Unfortunately, his on-off stats this post-season are most similar to 2010: the team had a net rating of 4.6 back in 2010 with a total on-off of 23.2 — so yes, they were 23.2 points per 100 possessions better with him on the court. But James ran out of fuel after a couple of failed runs to the Finals, and he decided to join up with other stars on another team after his super-human efforts were wasted. Cavaliers fans can point to how his incredible stats mimic what he did when he was younger, but they’d better hope the similarity ends in the box score.

— Justin Willard (@AcrossTheCourt)

Defensive matchups

As with every series that involves the Cavs, this one boils down to whether anyone can contain the King.

LeBron James has been unstoppable through the first two rounds. He leads all players with 34 points on over 41 minutes per game. His true shooting stands at an efficient 63 percent on 35 percent usage. If he maintains his current performance, then his 11 assists per 100 possessions and 2.9 assist-to-turnover ratio would be his highest in a postseason.

How will the Celtics deal with this tour de force?

The following chart shows how Boston matched up defensively against Cleveland during the regular season. The lines indicate the defenders who spent the most time guarding specific offensive players on a given possession. The thicker the line, the more frequent the matchup.

While Jaylen Brown and Marcus Morris have spent a total of 57 and 55 defensive possessions, respectively, on James, the numbers are more nuanced when we look at them at the game level. Brown served as the primary defender on 49 possessions in the first Cavs-Celtics game. That was on Opening Night back in mid-October, when Morris was inactive. Thereafter, the 6-foot-9 forward assumed the bulk of the responsibility for James, with Semi Ojeleye providing backup. It seems likely that Morris will draw most of the assignment yet again.

— Positive Residual (@presidual)

Offensive styles

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 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.

On the graph below you’ll see a line for each team’s offense. As the line moves away from the center of the graph on each axis you’re seeing more of that stylistic trait. For example, shot selection shows a (hypothetically) more efficient shot selection the further you are from center. Here’s how the Celtics and Cavaliers match up.

The Cavaliers offense was much more efficient than Boston’s in the regular season but they’re reliance on LeBron’s gravity to create shots for everyone else will be tested by Boston’s wing defenders. On the other end, Boston still uses a minimum of movement and gets a lot of mileage out of the penetration abilities of Terry Rozier and Jayson Tatum. They’ll need those creators to continue to be sharp if they are going to have a chance of outscoring Cleveland.

— Ian Levy (@HickoryHigh)

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.

In a rematch of last year’s Eastern Conference Finals, the Brad Stevens Celtics face the LeBron James in what projects to be a really competitive series. Despite not having homecourt advantage, the Cavaliers come in as favorites (57 percent to win) based off a superior playoff rating in my system (Cavaliers have a +4.4 rating, Celtics have a +2.8 rating).

Whichever team wins this series would likely be a heavy underdog in the NBA Finals, as both the Rockets and Warriors have playoff ratings greater than +10. The most likely outcome is the Cavaliers winning in six, but both teams have three scenarios with at least a 10 percent chance of occurring. The Celtics’ elite defense may be enough to slow down LeBron, while their offense should look good against the Cavaliers’ poor defense. The series will likely be more competitive than some expect, but look for the Cavaliers to move on to their fourth consecutive NBA Finals appearance on the back of another amazing playoff run by LeBron James.

— Jacob Goldstein (@JacobEGoldstein)