Ending the Year on a High Note…or should I say Basketball Note

Deeper analysis on what constitutes MVP Value

Blog 35 photo

In my blog post dated February 3, 2017, I discussed several statistics that are noteworthy in analyzing how much a basketball player contributes to his team’s success. In it, I compared Stephen Curry and Russell Westbrook using several advanced statistics that are not typically highlighted.

The first statistic: Primary plus Secondary Assists per Minute a player has the ball. Time with the ball equates to assist opportunity, so holding the ball most of the time one’s team is on offense reduces the opportunity for others on the team to have assists. This may lead to fewer assisted baskets for the whole team, but more for the individual player. As of the time of the post, Curry had 1.74 assists (primary plus secondary) per minute he had the ball, while Westbrook only had 1.30 assists per minute. Curry’s efficiency in assists is one of the reasons the Warriors total almost 50% more assists per game than the Thunder, make many more easy baskets, and lead the league in field goal percentage.

The second statistic: Effective Field Goal Percentages (where making a 3-point shot counts the same as making 1 ½ 2-point shots). Again, Curry was vastly superior to Westbrook at 59.1% vs 46.4%. What this means is that Westbrook scores more because he takes many more shots, but these shots are not very efficient for his team, as Westbrook’s shooting percentage continued to be well below the league average of 45.7% (Westbrook’s was 42.5% last season and is 39.6% this season to date).

The third statistic: Plus/Minus.  Plus/Minus reflects the number of points your team outscores opponents while you are on the floor.  Curry led the league in this in 2013, 2014, and 2016 and leads year-to-date this season. In 2015 he finished second by a hair to a teammate. Westbrook has had positive results, but last year averaged 3.2 per 36 minutes vs Curry’s 13.8. One challenge to the impressiveness of this statistic for Curry is whether his leading the league in Plus/Minus is due to the quality of players around him. In refute, it is interesting to note that he led the league in 2013 when Greene was a sub, Durant wasn’t on the team and Thompson was not the player he is today.

The background shown above brings me to today’s post which outlines another way of looking at a player’s value. The measurement I’m advocating is: How much does he help teammates improve? My thesis is that if the key player on a team creates a culture of passing the ball and setting up teammates, everyone benefits. Currently the value of helping teammates is only measured by the number of assists a player records. But, if I’m right, and the volume of assists is the wrong measure of helping teammates excel (as sometimes assists are the result of holding the ball most of the time) then I should be able to verify this through teammate performance. If most players improve their performance by getting easier shots when playing with Westbrook or Curry, then this should translate into a better shooting percentage. That would mean we should be able to see that most teammates who played on another team the year before or the year after would show a distinct improvement in shooting percentage while on his team. This is unlikely to apply across the board as some players get better or worse from year to year, and other players on one’s team also impact this data. That being said, looking at this across players that switch teams is relevant, especially if there is a consistent trend.

To measure this for Russell Westbrook, I’ve chosen 5 of the most prominent players that recently switched teams to or from Oklahoma City: Victor Oladipo, Kevin Durant, Carmelo Anthony, Paul George and Enes Kantor. Three left Oklahoma City and two went there from another team. For the two that went there, Paul George and Carmelo Anthony, I’ll compare year-to-date this season (playing with Westbrook) vs their shooting percentage last year (without Westbrook). For Kantor and Oladipo, the percentage last year will be titled “with Westbrook” and this year “without Westbrook” and for Durant, the seasons in question are the 2015-16 season (with Westbrook) vs the 2016-17 season (without Westbrook).

Shooting Percentage

Table 0

Given that the league average is to shoot 45.7%, shooting below that can hurt a team, while shooting above that should help. An average team takes 85.4 shots per game, so a 4.0% swing translates to over 8.0 points a game. To put that in perspective, the three teams with the best records this season are the Rockets, Warriors and Celtics and they had first, second and fourth best Plus/Minus for the season at +11.0, +11.0 and +5.9, respectively. The Thunder came in at plus 0.8. If they scored 8 more points a game (without giving up more) their Plus/Minus would have been on a par with the top three teams, and their record likely would be quite a bit better than 12 and 14.

Curry and His Teammates Make Others Better

How does Curry compare? Let’s look at the same statistics for Durant, Andrew Bogut, Harrison Barnes, Zaza Pachulia and Ian Clark (the primary player who left the Warriors). For Barnes, Bogut, Pachulia and Durant I’ll compare the 2015 and 2016 seasons and for Clark I’ll use 2016 vs this season-to-date.

Table 1

So, besides being one of the best shooters to play the game, Curry also has a dramatic impact on the efficiency of other players on his team. Perhaps it’s because opponents need to double team him, which allows other players to be less guarded. Perhaps it’s because he bought into Kerr’s “spread the floor, move the ball philosophy”. Whatever the case, his willingness to give up the ball certainly has an impact. And that impact, plus his own shooting efficiency, clearly leads to the Warriors being an impressive scoring machine. As an aside, recent Warrior additions Casspi and Young are also having the best shooting percentages of their careers.

Westbrook is a Great Player Who Could be Even Better

I want to make it clear that I believe Russell Westbrook is a great player. His speed, agility and general athleticism allow him to do things that few other players can match. He can be extremely effective driving to the basket when it is done under control. But, he is not a great outside shooter and could help his team more by taking fewer outside shots and playing less one/one basketball. Many believed that the addition of George and Anthony would make Oklahoma City a force to be reckoned with, but to date this has not been the case. Despite the theoretic offensive power these three bring to the table, the team is 24th in the league in scoring at 101.8 per game, 15 points per game behind the league leading Warriors. This may change over the course of the season but I believe that each of them playing less one/one basketball would help.

They got it right: Why Stephen Curry deserves to be a First Team All-Star

Curry vs. Westbrook

Much has been written about the fact that Russell Westbrook was not chosen for the first team on the Western All-Stars. The implication appears to be that he was more deserving than Curry. I believe that Westbrook is one of the greatest athletes to play the game and one of the better players currently in the league. Yet, I also feel strongly that so much weight is being placed on his triple doubles that he is being unfairly anointed as the more deserving player. This post takes a deeper dive into the available data and, I believe, shows that Curry has a greater impact on winning games and is deserving of the first team honor. So, as is my want to analyze everything, I spent some time dissecting the comparison between the two.  It is tricky comparing the greatest shooter to ever play the game to one of the greatest athletes to ever play, but I’ll attempt it, statistic by statistic.

 

Rebounding

Westbrook is probably the best rebounding guard of all time (with Oscar Robertson and Magic Johnson close behind). This season he is averaging 10.4 rebounds per game while Curry is at 4.3. There is no question that Westbrook wins hands down in this comparison with Curry, who is a reasonably good rebounding point guard.  But on rebounds per 36 minutes played this season, Westbrook’s stats are even better than Oscar’s in his best year. In that year, Robertson averaged 12.5 rebounds playing over 44 minutes a game which equates to 10.2 per 36 minutes vs Westbrook’s 10.8 per 36 minutes (Magic never averaged 10 rebounds per game for a season).

 

Assists

You may be surprised when I say that Curry is a better assist producer than Westbrook this season. How can this be when Westbrook averages 10.3 assists per game and Curry only 6.2?  Since Oklahoma City plays a very different style of offense than the Warriors, Westbrook has the ball in his hands a much larger percentage of the time. They both usually bring the ball up the court but once over half court, the difference is striking. Curry tends to pass it off a high proportion of the time while Westbrook holds onto it far longer. Because of the way Curry plays, he leads the league in secondary assists (passes that set up another player to make an assist) at 2.3 per game while Westbrook is 35th in the league at 1.1 per game. The longer one holds the ball the more likely they will shoot it, commit a turnover or have an assist and the less likely they will get a secondary assist. The reason is that if they keep the ball until the 24 second clock has nearly run out before passing, the person they pass it to needs to shoot (even if the shot is a poor one) rather than try to set up someone else who has an easier shot. For example, if a player always had the ball for the first 20 seconds of the 24 second clock, they would likely have all assists for the team while on the court.

Table 1: Assist Statistic Comparison

Curry vs. Westbrook Assists
*NBA.com statistics average per game through Feb 1st, 2017

When in the game, Westbrook holds the ball about 50% of the time his team is on offense, he gets a large proportion of the team’s assists. But that style of play also means that the team winds up with fewer assists in total. In fact, while the Warriors rank #1 in assists as a team by a huge margin at 31.1 per game (Houston is second at 25.6), Oklahoma City is 20th in the league at 21.2 per game. If you agree that the opportunity to get an assist increases with the number of minutes the ball is in the player’s possession, then an interesting statistic is the number of assists per minute that a player possesses the ball (see Table 1). If we compare the two players from that perspective, we see that Curry has 1.27 assists per minute and Westbrook 1.17. Curry also has 0.47 secondary assists per minute while Westbrook only 0.13. This brings the total primary and secondary assist comparison to 1.74 per minute of possession for Curry and 1.30 for Westbrook, a fairly substantial difference. It also helps understand why the Warriors average so many more assists per game than Oklahoma City and get many more easy baskets. This leads to them having the highest field goal percentage in the league, 50.1%.

 

Shooting

Russell Westbrook leads the league in scoring, yet his scoring is less valuable to his team than Stephen Curry’s is to the Warriors. This sounds counterintuitive but it is related to the shooting efficiency of the player: Curry is extremely efficient and Westbrook is inefficient as a shooter. To help understand the significance of this I’ll use an extreme example. Suppose the worst shooter on a team took every one of a team’s 80 shots in a game and made 30% of them including two 3-point shots. He would score 24 baskets and lead the league in scoring by a mile at over 50 points per game (assuming he also got a few foul shots). However, his team would only average 50 or so points per game and likely would lose every one of them. If, instead, he took 20 of the 80 shots and players who were 50% shooters had the opportunity to take the other 60, the team’s field goals would increase from 24 to 36. Westbrook’s case is not the extreme of our example but none-the-less Westbrook has the lowest efficiency of the 7 people on his team who play the most minutes. So, I believe his team overall would score more points if other players had more shooting opportunities. Let’s look at the numbers.

Table 2: Shot Statistic Comparison

shots-table
*NBA.com statistics average per game through Feb 1st, 2017

Westbrook’s shooting percentage of 42.0% is lower than the worst shooting team in the league, Memphis at 43.2%, and, as mentioned is the lowest of the 7 people on his team that play the most minutes. Curry has a 5.5% higher percentage than Westbrook. But the difference in their effectiveness is even greater as Curry makes far more three point shots. Effective shooting percentage adjusts for 3 point shots made by considering them equal to 1½ two point shots. Curry’s effective shooting percentage is 59.1% and Westbrook’s is 46.4%, an extraordinary difference. However, Westbrook gets to the foul line more often and “true shooting percent” takes that into account by assuming about 2.3 foul shots have replaced one field goal attempt (2.3 is used rather than 2.0 to account for 3 point plays and being fouled on a 3-point shot). Using the “true shooting percentage” brings Westbrook’s efficiency slightly closer to Curry’s, but it is still nearly 10% below Curry (see table 2). What this means is very simple – if Curry took as many shots as Westbrook he would score far more. In fact, at his efficiency level he would average 36.1 points per game versus Westbrook’s 30.7. While it is difficult to prove this, I believe if Westbrook reduced his number of shots Oklahoma City would score more points, as other players on his team, with a higher shooting percentage, would have the opportunity to shoot more. And he might be able to boost his efficiency as a shooter by eliminating some ill-advised shots.

 

Turnovers vs Steals

This comparison determines how many net possessions a player loses for his team by committing more turnovers than he has steals. Stephen Curry averages 2.9 turnovers and 1.7 steals per game, resulting in a net loss of 1.2 possessions per game. Russell Westbrook commits about 5.5 turnovers per game and has an average of 1.6 steals, resulting in a net loss of 3.9 possessions per game, over 3 times the amount for Curry.

 

Plus/Minus

In many ways, this statistic is the most important one as it measures how much more a player’s team scores than its opponents when that player is on the floor. However, the number is impacted by who else is on your team so the quality of your teammates clearly will contribute.  Nonetheless, the total impact Curry has on a game through high effective shooting percent and assists/minute with the ball is certainly reflected in the average point differential for his team when he is on the floor. Curry leads the league in plus/minus for the season as his team averages 14.5 more points than its opponents per 36 minutes he plays.  Westbrook’s total for the season is 41st in the league and his team averages +3.4 points per 36 minutes.

 

Summing Up

While Russell Westbrook is certainly a worthy all-star, I believe that Stephen Curry deserves having been voted a starter (as does James Harden but I don’t think Harden’s selection has been questioned). Westbrook stands out as a great rebounding guard, but other aspects of his amazing triple double run are less remarkable when compared to Curry. Curry is a far more efficient scorer and any impartial analysis shows that he would average more points than Westbrook if he took the same number of shots. At the same time, Curry makes his teammates better by forcing opponents to space the floor, helping create more open shots for Durant, Thompson and others. He deserves some of the credit for Durant becoming a more efficient scorer this year than any time in his career. While Westbrook records a far larger number of assists per game than Curry, Curry is a more effective assist creator for the time he has the ball, helping the Warriors flirt with the 32-year-old record for team assists per game while Oklahoma City ranks 20th of the 30 current NBA teams with 10 less assists per game than the Warriors.