Why do advanced statistics hate Kobe Bryant? Part 1

Ed. Note:  When you're done reading this post, make sure to go read Part 2, the follow-up post in which C.A. really digs into the numbers to explain why PER undervalues Kobe Bryant.

If you've got a lot of time with nothing to do, go into any NBA chat room or message board and ask the following question: 

Who is the best player in the NBA? 

It's a fun subject to dive into, as long as you are running with the right crowd.  If people stay respectful and stick to arguing things on merit, making points based on logic, evidence and knowledge-based observation, it can be a jolly good time, with many different answers, each with their own valid points.  You could go with LeBron James, the do-everything superstar.  He scores, he passes, he rebounds, he makes julienne fries.  If efficiency is your style, you could drop Chris Paul in the conversation.  Nobody is better at turning the ball in his hands into points on the board for his team, either through extremely proficient shooting or very adept passing.  If you like the big play, maybe Dwyane Wade is your man.  He scores with the best of them, and does it all in a way that looks great on SportsCenter.  If big men are your cup du jour, you could go with the young stud, Dwight Howard, or the old guard, Tim Duncan and Kevin Garnett.  And, of course, this conversation wouldn't even be interesting if you didn't include Kobe Bryant.

There are tons of fans who put Kobe on the top of that list.  Sure, lots of them are homeristic Laker lovers who create that list as much with their hearts as with their heads.  But they aren't alone.  There are plenty of NBA personnel who put Kobe at the top, or very near the top, of that list as well.  He was second in the MVP balloting last season, behind LeBron James.  A survey of NBA GMs ranked Kobe as 2nd most likely to win the MVP this season, and ranked him first in categories like "The player you'd most like to take a shot with the game on the line".  In that same survey, the question was asked "If you were starting a franchise and could sign any NBA player, which player would you sign?"  Kobe came in 3rd, behind LeBron and Dwight Howard, despite being more than 7 years older than some very attractive candidates like Wade and Paul.  The point in all this?  Kobe is very, very highly regarded in this league, both by people who think with their hearts, and people who don't.

So if I were to put a group of names in a list like this: 

LeBron James, Dwyane Wade, Chris Paul, Kobe Bryant

and ask you "Which of those players doesn't belong, and why?",  it might be a tough task.  You might think "Kobe is older than the other players" and you'd be right.  You might think "only LeBron isn't a guard."  But if I were to ask you "Which player on this list is significantly worse than the other three?", you'd be hard pressed to come up with an answer.  They're all incredible, right?

Not according to advanced statistical metrics, they aren't.  In fact, according to advanced statistics, Kobe Bryant is a distant fourth to the other three players.  According to the most well known advanced statistic, Player Efficiency Rating (PER), Kobe was the 6th most productive player in the league last year, barely registering above Brandon Roy.  He wasn't even the most valuable player on his own team, according to the Win Shares method (Pau Gasol) and the Adjusted +/- method (Lamar Odom).  No matter the method, Paul, Wade and James comprise the top 3.  No matter the method, Kobe is not ranked in the top 5.  That's a pretty big disconnect with what was described earlier.  In a two part piece, I will look at one particular advanced stat (PER), break it down to its individual components, and compare Kobe to other players in an effort to fully explain the disconnect between Kobe's analytical place in the game, and his statistical place in the game.

Now, I like to think of myself as a fairly open-minded Lakers fan.  I don't think Kobe is the best player in the NBA.  I give that honor to LeBron James.  This is not to say that Lakers fans who do think Kobe is #1 are not open-minded.  They are entitled to that opinion, and many of them could give you very good reasons why they think it to be true.  In the end, this is a matter of opinion and there are no right or wrong answers, only well and poorly reasoned ones.  I only mention my open-mindedness, and the subsequent evidence, as justification for the point I'm trying to make.  Like I said, I don't think Kobe is the best player in the NBA.  But not in the top 5?  That's ludicrous, blasphemous, and just plain crazy.  

Chris Paul and Dwyane Wade are terrific players.  I'd be willing to listen to arguments that they are peers of Kobe Bryant.  But for someone to suggest that, not only are they Kobe's peers, but far and away his superior, I just can't get on board with that.  And yet, here come advanced statistics to tell us that Wade and Paul, along with James, aren't just better than Kobe is right now.  They are better than Kobe has ever been, by a significant margin.  Last season, LeBron James had a PER of 31.76.  Dwyane Wade's PER totaled 30.46.  Chris Paul clocked in with a round 30.04.  Kobe Bryant?  24.46.  In fact, the highest PER Kobe has ever had came in 2005-2006, when he topped out at 28.0.  It's good, to be sure, but nowhere near as good a season, statistically, as any of these three players had last year.   In order to figure out why, the first step is to get a truly thorough understanding of PER.

PER is the brain child of John Hollinger, probably the biggest name in the NBA stats world not employed by an NBA franchise.  Hollinger writes for ESPN, and relies heavily on PER to determine predictions he makes about, well, everything.  Which teams are going to be the most successful, which players are going to have breakout years, who the MVP is, almost all of his work is more or less related to PER.  Love him or hate him, agree with him or think he's full of crap, you simply have to respect that he is probably the most successful "stat-geek" in the NBA, with the possible exception of Daryl Morey.  So what, exactly, is PER?

PER is a catch-all stat which looks at every statistical aspect of an NBA player's game, and incorporates it into one simple number.  Don't know how to measure the greatness of a point guard like Chris Paul against the production of a big man like Tim Duncan?  That's what PER is for.  It is regulated in every way that a stat can be.  It is pace adjusted, so players from teams that play faster won't get inflated numbers.  It's per minute, so players who play more have no advantage over players that play less.  Hollinger creates these ratings for every player in the league, and then adjusts them so that the "average" NBA player in a given year has a rating of 15.00.   PER has it's limitations, mainly in terms of assessing quality defense, and Hollinger himself is not blind to the fact that PER is not the "be all, end all" in terms of player evaluation.  Or, at least, that's what he says, right before saying that PER clearly shows that LeBron James is having one of the greatest seasons in the history of the NBA, and is performing at a level that hasn't been seen since the days of Micheal Jordan.

After a lot of description, we're still no closer to what actually makes up PER.  For that, I have to show you the formula, and I'm doing so only so that I can show off and you can know exactly how much time I've wasted preparing for this topic.  You see, the formula for PER is enough to make all but the most statistically inclined very queasy.   In fact, I can't even make it fit on our blog.  Please click here, courtesy of Wikipedia, to see what I'm talking about.  (If you don't approve of this being displayed, Mr. Hollinger, you have my sincere apologies). 

Did you really look at the formula?  If you tried to cheat without taking a peek, please go back and take a look.  Otherwise, you will fail to be sufficiently impressed when I tell you that I manually (and by manually, I mean in Excel) calculated Kobe's PER from last season.  Why would I engage in such a ridiculous task?  So that I could bring you Kobe's PER, broken down by each individual component.  When broken down this way, we can see that PER credits a player for the positive aspects of his production, represented by the positive numbers in the table below, and balances those against the negative aspects of his production, represented by the negative numbers below. Positive production includes field goals and free throws made, assists, rebounds, blocks and steals. Negative production includes fouls committed, turnovers and field goals and free throws attempted. FGAs and FTAs are treated as negative because they use up a team's limited number of possessions.

So, without further adieu, here is Kobe's PER from the 2008-2009 season, broken down by individual component.

Player	3 pt	Assist	FG	FT	TO	FGA	FTA	DRB	ORB	STL	BLK	PF	PER
Kobe Bryant	2.01	4.53	22.55	7.43	-3.77	-11.99	-0.54	1.63	1.18	2.15	0.49	-1.16	24.50

 

A couple of quick notes regarding this calculation.  I was unable to get any closer to Kobe's actual PER (24.46) than this.  Please forgive and accept the relatively small margin of error.  If you don't trust me, by all means break out your graphing calculator and add up all the factors.  Or you could just trust that the numbers are real.

With that out of the way, lets take a look and find out what we see.  Assists are good for roughly 20% of the overall number.  3 pointers and field goals (basically, shots from the field) account for roughly 12.5 points, or just about half of the overall score (I'm combining the positive values for FG and the negative values for FGA, if you are following along at home).  Free throws account for another 7 points, so total scoring is almost 80% of the overall score.  Rebounding and defensive stats basically cancel out with turnovers and personal fouls.

So, the appropriate conclusions we can gather from this are:  Kobe's defense and rebounding are about as valuable as his turnovers and fouls are detrimental.  Kobe's assists are only 20% of his value as a player, and the rest of his value is determined by his ability to score.  Kobe's ability to get to the free throw line is worth almost as much as his ability to score from the field.  Whether you agree with any of these statements is irrelevant, we're just trying to make sense of what PER is telling us about Kobe's value on the court. 

If you've figured out that these numbers mean absolutely nothing unless compared to somebody else, you are 100% right.  So tune in tomorrow, as I compare Kobe's individual PER components to some other players you might have heard of, and then try to bring it all together and make sense of it all.  Until then, keep your feet on the ground and keep reaching for the stars.