Pushing the Boundaries of the Four Factors
Posted by Zach Lowe on Nov 10, 2009
Barring a change in the roster or the team’s style of play, the 2010 Celtics have a chance to answer this question: Can a team contend for an NBA title despite ranking near the bottom of the league in three of the so-called Four Factors of winning on offense? No team has come close to doing so in the No Hand Check era (i.e., since 2004). The C’s may provide the best test so far.
Dean Oliver pioneered the so-called Four Factors of winning, the four variables on offense (and the corresponding four on defense) that have the greatest impact in deciding who wins a basketball game. Do these four things well, and your team will usually win.
For the uninitiated, The Four Factors:
1) Effective Field Goal Percentage (offense) and Effective Field Goal Percentage allowed (on defense)—a stat that adjusts regular FG% to account for the fact that three-pointers are worth more than regular field goals.
2) Offensive Rebounding Percentage: The percentage of available offensive rebounds your team gets. If the C’s miss 40 shots and rebound 10 of them, their ORB % is 25 percent. (The defensive version of this factor is Defensive Rebounding Percentage).
3) Turnover Percentage: How many of a team’s offensive possessions end in turnovers? (The defensive version measures how often your team forces turnovers).
4) Free Throw Attempts/Field Goal Attempts: How often does your team get to the foul line on offense? (The defensive version measures how often a team sends opponents to the foul line).
Before addressing the offensive Four Factors, let’s say this up front: The C’s are an incredible defensive team. Right now, they are the only team in the NBA to rank in the top 10 in all Four Factors defensively, according to Basketball Reference.
Still: No team has even gotten to the conference finals since 2004 while ranking as poorly as the C’s project to rank in three of the Four Factors on offense.
Right now, the C’s rank:
2nd in Effective Field Goal %
18th in Turnover %
25th in Offensive Rebounding %
25th in FTA/FGA ratio
In other words: The Celtics shoot exceptionally while turning the ball over a lot and rarely grabbing offensive boards or getting to the foul line. And that 18th ranking in turnover % is a big improvement; the team finished 29th in that category in each of the last two seasons.
The big drops so far this year have been in free throw attempts and offensive rebounding; the C’s ranked in the top 10 in each category last season. The fall-off isn’t entirely surprising—the C’s lost their best offensive rebounder and most prolific foul-drawer (Leon Powe) and replaced him with Rasheed Wallace, who does little of either at this stage in his career. The team’s other solid offensive rebounder (Glen Davis) punched his friend in the face and broke his thumb.
Davis will eventually help the ORB numbers and the maybe the free throw attempts. But this team projected poorly in each category before Baby’s injury; one of the stat systems they use over at Basketball Prospectus predicted huge drops in each category.
So: Can you win a title ranking, say, 25th or worse in three of the Four Factors on offense? What about 20th or worse?
Of course, we don’t know. But we do know this: No team has made the conference finals since 2004 while ranking 20th or worse in three of the factors on offense. Of the 20 conference finalists since ’04, only one (the 2006 NBA champion Miami Heat) ranked 15th or worse in three categories (though that Heat team ranked no lower than 18th in any of them) .
A small handful of those 20 teams have been terrible at two of the four factors on offense, but not three. More than a handful have been outstanding at one and league-average at the other three, but, again, none have been truly bad at three of the Four Factors—on offense.
Here are some interesting cases:
The 2008 Spurs ranked 26th in offensive rebounding % and 24th in FTA/FGA but 10th in eFG% and 7th in turnover rate. Any Spurs fan could tell you the team hasn’t pounded the ball inside much in the last two seasons (thus the low foul-drawing rate) and basically punts offensive rebounding to focus on transition defense. Like the C’s, they shot the ball well. Unlike the C’s, they took care of it.
Ditto for the 2007 Spurs. The NBA champs that season ranked 27th in ORB and 20th in FTA/FGA—both well below average. But they ranked 2nd in eFG% and 8th in turnover percentage. Again, a very similar offensive profile to this year’s Celtics—with the (rather large) exception of turnovers.
(The Seven Seconds or Less Suns of 2005 and 2006 put up very similar profiles, with the 2006 squad finishing dead last in ORB% and FTA/FGA but 1st and 2nd in the other two categories).
The 2005 Finals between the Pistons and the Spurs provides some encouragement for the C’s; both teams were mediocre offensive units (especially Detroit) and yet both won because they were outstanding defensively. But even their offensive Four Factor rankings weren’t as extreme as Boston’s might end up:
’05 Spurs: 8th in eFG%, 12th in Turnover %, 13th in ORB% and 21st in FTA/FGA
’05 Pistons: 23rd, in eFG%, 13th in TO%, 4th in ORB% and 14th in FTA/FGA
The thing is, I believe the Celtics can contend for a title as currently constructed. The one offensive factor they are good at (creating good shots and making those shots) is especially powerful—and the C’s are really good at it. And you can live with a lack of offensive rebounding if it means the team will excel at transition defense.
And the low foul-drawing rate? We’ll see if that holds up when the stakes are highest and Paul Pierce decides to attack the basket more aggressively.
There’s also the hope that the team’s early improvement in turnover rate will last. Rasheed Wallace has an extremely low turnover rate (much lower than Powe’s), and two of the team’s younger guys (Rondo and Perk) will likely turn the ball over less as they mature. (Perk has led the team’s regulars in turnovers the last two seasons, in part because of all those damn moving screen calls).
Can the C’s win the title the way they are now? I say they can. But their job would be a lot easier if they could get better at one of these three factors. Get to it, Doc.
Note: Here’s the ranking of the 20 conference finalists since 2004 based on the sum of their offensive Four Factors rankings. (Example: A team that ranked 1st in all four categories would score a 4; lower is better). The ’06 Mavs blow everyone away. League champions in bold.
1) 2006 Mavericks: 25
2) 2007 Jazz: 32
3) 2009 Lakers: 35
4) 2008 Pistons: 37
5) 2009 Cavs: 39
6) 2008 Lakers: 41
7) 2006 Pistons: 42
2009 Nuggets: 47
9) 2005 Heat: 48
10) 2005 Suns: 50
11) 2007 Pistons: 51
12) 2006 Heat: 52
13) 2005 Spurs: 54
13) 2005 Pistons: 54
13) 2008 Celitcs: 54
16) 2007 Cavs: 55
17) 2009 Magic: 56
18) 2007 Spurs: 57
19) 2006 Suns: 63
20) 2008 Spurs: 67
What’s fascinating about this list and this topic in general is just how many ways there are to be successful in the NBA. The Nuggets win because they play good defense, get to the foul line a lot and pound the hell out of the boards. The Spurs win because they shoot well, take care of the ball and play solid defense. Two completely different offensive styles with similarly successful results.
The NBA is endlessly fascinating.
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