Tag: NBA

Basketball, NBA

Using SportVU to find the most overrated defenders in the NBA

dj block

By: Patrick Harrel

In the quest for advanced statistics capable of accurately quantifying defense, NBA analysts have always faced an uphill battle. Unlike offense, which had easily quantifiable measures of success, readily available statistics came nowhere close to establishing how effective a defensive player was on the floor. If a player blocked a lot of shots, he was often lauded as a tremendous defender, but what if those blocks came at the cost of missed rotations and wide open layups on failed attempts? Until very recently, we couldn’t dream of answering a question like that comprehensively.

When the NBA announced this year that they would be making the SportVU data available to the public for the 2013-14 season, the news was met with raucous applause from all circles involved with basketball. Writers loved it, fans loved it, and statisticians, who had always only been able to make educated guesses about certain factors, adored it. At Princeton Sports Analytics, we are going to make the data more accessible to you in a bi-weekly column, with each entry dedicated to a specific aspect of what is going on in the NBA.

If you are unfamiliar with SportVU, it is a system that is now installed in all 29 NBA arenas that tracks the movement of all 10 players on the court, the 3 referees, and the ball, and automatically generates an incredible amount of data about the various outcomes on the floor. It tracks average speed of every player, how many touches any given player gets per game, and much more.

Today, we’re going to discuss the ability to better quantify defense. Specifically, we will look at who have been some of the surprisingly poor interior defensive players this season. SportVU measures how well players defend inside by charting every shot attempt that an offensive player takes when a defender is both within five feet of the basket and within five feet of the offensive player. It then measures what percentage of shots the defensive player allows to be made under these conditions.

Continue reading “Using SportVU to find the most overrated defenders in the NBA”

princetonsportsanalyticsLeave a comment
Basketball, NBA

Past Achilles injuries show that Kobe Bryant’s #NBArank is more than generous

By: Patrick Harrel

Kobe Bryant recently changed his twitter avatar to a simple image of the numbers “1225,” an obvious nod to ESPN’s respective predictions for the Lakers performance in the West and Kobe’s performance this season in comparison to his NBA counterparts. He, along with Laker Nation, was appalled to see both ranked so poorly. The NBA Rank methodology may be a bit primitive, with each voter voting on a 1-10 integer scale to rate all the NBA players on the list, but the ranking nonetheless reflects a reality that Kobe is likely to regress after rupturing his Achilles tendon.

But how much will he regress? Dr. Douglas Cerynik and Dr. Nirav H. Amin of Drexel University did some research into Achilles ruptures in their paper Performance Outcomes After Repair of Complete Achilles Tendon Ruptures in National Basketball Association Players, and shed some light as to just how difficult it is to come back from an Achilles tear. Of the 18 players they looked at, 7 were never able to return to NBA action, 3 returned for just one season, and the remaining 8 would go on to play 2 or more seasons.

And of those players that did return, their performance suffered drastically, especially in their first season back. In their study of the 11 players that returned to the NBA, the players PER (player efficiency rating), decreased by an average of 4.57 points. In the second, it decreased by 4.38 points. Even after controlling for age and other confounding variables, both figures were statistically significant, the first with a p-value of .038 and the second with a p-value of .081.

If you are unfamiliar with PER, it is an attempt at an all-encompassing rating system that sets the league average at 15. An All-Star typically has a PER in the range of 21 or above, and an MVP will be in the 27-30 range. Last year, Kobe had a PER of 23.10. If his PER fell by the mean decrease seen in the study of 4.57 in 2013-14, it would be 18.53, or .07 points worse than Samuel Dalembert’s PER last year. When Kobe is compared to the mediocre center the Mavericks just signed as a stopgap to please the fan base in Dallas, he suddenly doesn’t seem so intimidating.

Continue reading “Past Achilles injuries show that Kobe Bryant’s #NBArank is more than generous”

princetonsportsanalytics1 Comment
Basketball, NBA

Regarding Rebounds

By Avi Cohen All basic sports statistics need to be simple enough for the regular sports fan to comprehend quite readily, allowing them to understand the basics of how a player or team performed without actually watching the game. As a result of this simplicity, most are pretty flawed in some way or another when taken out of context. For instance, a typical stat line … Continue reading Regarding Rebounds

princetonsportsanalyticsLeave a comment
Basketball, NBA

Let the NBA Back in Seattle, But Not Who You Think

The case for the Clippers to leave Los Angeles for Seattle by Dylan Ackerman In the last couple of weeks, like many Americans, I find myself intrigued with happenings in the NBA. Unlike most people following basketball, however, my interested has nothing to do with anything happening on the court. I am not completely sure how – perhaps my love of Starbucks, perhaps my desire … Continue reading Let the NBA Back in Seattle, But Not Who You Think

princetonsportsanalytics1 Comment
Basketball, NBA

Transition Offense Has Pushed the Houston Rockets Into Relevance

By Patrick Harrel

rockets wings

When the Rockets acquired James Harden three days before Opening night, they completed a whirlwind of a summer that saw them trade or release 8 of their 10 rotation players from the previous year, including all five opening day starters from 2011. The longest tenured member on the team? Patrick Patterson, a third year player who would take over the starting power forward spot despite only having started seven games.

And the most experienced starter? Chandler Parsons, a second round pick from the previous season who had taken over the starting spot from Chase Budinger early in the 2011-12 campaign yet averaged just 9.5 points per game over the season.

With five rookies on the roster, just one player over the age of 26 (Carlos Delfino), and a combined 98 games started between the starting lineup, not much was expected of the Rockets. The team was, after all, by far the youngest in the league with just a 23.6 average age, and young teams do not have a vast history of success in the NBA.

However, after a 4-7 start, the team has vastly outperformed expectations, winning 12 out of 17 and 6 of their last 7 in order to move to 16-12 and into the sixth seed in the Western Conference. In these last seven games, they won five games against playoff teams from last year, including a three game streak of both scoring 120 and winning by over 20, matching an NBA record. They also broke both Memphis and Chicago’s defenses down badly, beating both team’s season high in points allowed on their way to blowout victories.

Now, they stand #1 in points scored per game and #8 in offensive efficiency, a remarkable feat for a squad that young.

The only question is how are they doing this? The duo of Asik and the Patterson projected to be somewhere between awful and god-awful this season, with Asik having more career foul-outs (2) than double-doubles (1), and Patterson shooting a cool 44% from the field as a power forward in 2011-12. Chandler Parsons started most of the season but rarely cracked into double figures in scoring.

Going into the year, it seemed like the team would be forced to ride James Harden and a still-injured Jeremy Lin extremely hard if they wanted to scrape out any modicum of respectability on the offensive side of the ball, but now they have a case to make as one of the most dynamic offenses in the league. What gives?

Turns out, it’s pretty basic: Just by outracing teams down the court on the break, the Rockets have improved their efficiency and gotten by despite a consistent half court attack. However, getting out on the break has not always been a path to success.

Since Synergy has begun charting games (the last three seasons), none of the league’s fastest teams have made the playoffs. However, unlike the past leaders in league pace, the Rockets not only get out on the break, they convert their looks.

Over the past three seasons, the league’s fastest teams have ranked 16th in the league in points per possession (PPP) in transition, with last year’s Sacramento Kings the only one to be above average in a year. The Rockets, on the other hand, are 9th in efficiency in transition, getting 1.18 PPP. To see how they’re exploiting their athleticism on the break, we’ll break down a couple of plays from the last week. Here’s one example from Saturday’s game against Memphis:

screenshot 1

After a Marcus Morris block, Carlos Delfino collects the ball and four Rockets turn and run up the court.

Continue reading “Transition Offense Has Pushed the Houston Rockets Into Relevance”

princetonsportsanalytics2 Comments