Nylon Calculus: Rockets-Warriors win probabilities, style, matchups and more
By Ian Levy
Currently, for the Rockets-Warriors series there’s a disconnect between the subjective evaluation of the teams, where the Warriors are heavily favored, and the actual numbers. The Rockets won more games, had the superior offensive rating in the regular season, had the superior defensive rating too, they have homecourt advantage, and even when you adjust for other factors you still see them as the series favorite, numerically. This is true for playoff stats too, which you can see below. Using their opponents’ adjusted net rating, you can see how every team has performed so far in the playoffs.
The Rockets are on top, followed by the Warriors. There are a few surprises — the 76ers lost to the Celtics but still had the better rating, thanks to how they did in the first round. The Pacers still have a better rating than the Cavaliers, who beat them in the first round. But the series went seven games and Indiana outscored them by roughly six points a game during it. And of course this is not perfect: it’s not adjusting for injuries or players changing their minutes from the regular season, like LeBron James.
In fact, this is a positive indicator for the Warriors. Their playoff net rating has nearly matched Houston’s, and Stephen Curry has only played four of their ten games. If Golden State’s roasting of the Spurs and Pelicans is a sign of the sleeping Warriors awakening, and if Curry can regain his peak form, you can indeed find the numbers that support them as favorites. You just have to dig around to support that conclusion, and that’s why so many analytic models still favor the Rockets.
— Justin Willard (@AcrossTheCourt)
Defensive matchups
How will Houston handle the “Hamptons Five”?
The Warriors’ vaunted lineup, which features Stephen Curry, Klay Thompson, Andre Iguodala, Kevin Durant and Draymond Green, appeared in four games during the second-round series against the New Orleans Pelicans. It was the starting unit in games four and five. In 54 total minutes, it outscored opponents by 41 points per 100 possessions, the highest net rating among playoff lineups with at least 25 minutes. It had a top-five offensive rating and a top-three defensive rating.
This sample, as small as it was, built upon the Hamptons Five’s regular-season resume. In 127 minutes, the lineup produced a net rating of +8 — impressive, though hardly fearsome. But, while it had its share of defensive struggles, its 125 offensive rating ranked in the top three among five-man units with at least 100 minutes. Based on the way it clicked against the Pelicans, as well as the long track records of the individual players, it presents a formidable challenge, to be sure — one that the Rockets will encounter for the first time this year, since Steve Kerr withheld it from the season series with Houston.
The following chart shows how the Rockets matched up defensively against the Warriors 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.
The Rockets have a bonafide top-10 defense this year. They boast a number of fantastic individual defenders with the size and versatility to match up with the key Warriors players. They can clearly stand toe-to-toe with Golden State. The question is whether they can put enough pieces together specifically to thwart the lineup that Kerr has been waiting to unleash.
— 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 Rockets and Warriors match up.
The Rockets and Warriors are both known for their shooting but they accomplish things in very different ways — movement, cutting and passing for the Warriors, the individual creation abilities of Chris Paul and James Harden for the Rockets. This series will be a sharp contrast and it’s hard to imagine either team disrupting the other’s offense to any significant degree.
— 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.
The series we have all been waiting for, the Rockets and Warriors finally meet in the NBA Fin… er Western Conference Finals. The Rockets come in a slight favorites in the series, mostly due to homecourt advantage. The two giants of the 2017-18 season rate as near equals in my playoff ratings, with the Rockets rating of +10.9 just outpacing the Warriors rating of +10.3. If ever a team had a chance to unseat the Warriors, it would be this years Rockets who can match or approach the star power, offensive prowess, and defensive tenacity the Warriors have shown over the past few seasons.
The most likely outcome is the Rockets winning in seven games (18.5 percent), with the Warriors winning in six (16.1 percent) as the second-most likely outcome. Overall, the series boosts a near 63 percent chance to go to six or seven games, hopefully living up to the potential it has for an all-time great playoff matchup.
Even if we assume that the Warriors of this regular season were not representative of their true strength, be it because of boredom or general complacency, and use the last two years of data to calculate the Warriors real strength, the Rockets are still ever so slightly favored in my model despite the Warriors playoff rating jumping to +11.3, nearly half a point better than the Rockets. In that scenario, where the past two years of data are used for the Warriors, the Rockets would have a 50.6 percent chance to win the series.
The Rockets have really been that good this year. This series could really go either way, but expect the homecourt advantage of the Rockets to eventually be enough to advance to the NBA Finals.
— Jacob Goldstein (@JacobEGoldstein)