How Does a Player Affect the TEAM'S Perfomance?

I hate the individual stats that are used for basketball these days. They don't describe the game.

See, the point of an individual player is not to try to rack up as many of the "good" stats and as few of the "bad" stats, even if that is what the popular models will try to to tell you. Nor will those stats alone tell you how good a player is, say , at rebounding, or passing. More rebounds than another player does NOT necessarily mean "better rebounder" any more than more assists means "better passer". The outcomes of those stats all depends on context, role on the team, teammates, and opposition.

But I like the team stats in aggregate. As a team, there is no "role", the point of the team IS to get as many points as possible, and to limit the other team's points as much as possible. If you do those two things, you have a winning team. That's why we love Dexter Fishmore's Points per Possession stats!

Points per possession is a great stat, but I don't have that easily at my disposal. But they do track team FG% on basketball-reference.com. I definitely buy in when I hear that a team has a high FG% and a low defensive FG%. On the same point, I don't judge an individual player on his particular FG% - it all depends on when the shot is taken, why it's taken, how difficult the shot is, what else was available. Most statistical models will say that two points is the same any other two points. But we know better don't we?

I hear a lot of people moaning about Kobe's low FG%, and then point to Pau's FG% and say that Pau should get more shots because of this. But aren't the two intertwined? Doesn't the play of Pau affect Kobe's FG%, and vice versa? Doesn't the entire team's play affect every other players' FG%? They are all in it together, working their individual roles to maximize the scoring of the team as a whole.

Let's take a look at the FG% of the 2009-2010 Los Angeles Lakers. Their FG% as a team was 45.7%. Who gets credit for this stat? The team does, duh. But who gets individual credit? You might say, well, whatever each individual's FG% is, that what they should be credited. But that's been my point - that's not how basketball works, you accumulate these stats as a team.

What if there were some way we could see what the team's FG% would be without a player, and what that same group of players' FG% would be with the player?

Surprise, surprise, all you need is a season where said player misses some games, and plays some other games. Take the FG% of the team without that player, and then take the FG% of the player with the team. Voila!

I present to you the FG% stats three players of their teams' FG% in games they missed, and their teams' FG% in games they played in:

Interesting isn't it? Looks like Lebron had the biggest effect on his team's FG% increasing their FG% 3.4 percentage points, compared to their "normal" state without him. Kobe is next at 2.2 percentage points, and Pau 1.1.

But what about each star's FG%? Remember how I said their individual % was dependent upon their role, and the type of shots they take for team? Lebron shot 50.3% last year, Pau 53.6%, Kobe 45.6%. What if we take them out of the equation, leaving behind only a comparison of the "other players" without the star versus their performance with the star? Then it looks like this:

So these are the FG% of only the "other players" when they are on their own versus when they play with each star.

Looking at this, it implies that Kobe actually improves other players' FG% by 2.3 percentage points, while Pau has no effect on them, and Lebron has a 0.5 percentage point effect.

This would be more accurate if I could figure out what the stats were for each minute the particular player did and did not play. Right now, I'm counting the whole games the players missed, but taking the FG% for the whole games the players played in (even though they did not play every minute).

But didn't I say the performance of the team overall is what mattered? OK, well by that measure Lebron got his team the higher FG%, including his own.

I picked FG% so I wouldn't have to adjust for pace and any of that.

So what does all this mean? To be honest, I don't know. We'd probably have to take a look at the defensive FG% for when the player was on and off the floor. But if someone could adjust for pace of the games, I'd like to know if the Hornets average fewer assists as a whole when Chris Paul comes out, which would imply that he's only redistributing the assists to himself when he plays, not raising the assist total of the entire team. I don't have the wherewithal to do this for the entire 2009-10 season, but I did take a sample of 7 consecutive games where CP3 averaged an "amazing" 14.4 assists per game. The team in aggregate averaged 23.9 assists per game during that stretch. I then took the previous 8 games that the Hornets played without CP3, and do you know how many assists per game they had as team for those games? 23.5.

Now before someone starts saying that I'm claiming CP3 is not a good passer, slow down there. I know the Hornets weren't winning without him. But I'm also saying that you shouldn't be judging how good he is by his gaudy assist numbers alone, because as you can see, the team got just as many assists with him as they did without him. There is no accounting of the quality of the assists, just the number.  And if you can see that, you can start to see how flawed it is to look at these types of individual outcomes as measures of a player's value to team. And until they improve the stats that are observed, this means any type of amalgams of these numbers, any formula using an individual's box score stats is flawed, because the basic premise is flawed, that "each individual player tries to accumulate as many good stats as possible for themselves and as few of the bad ones as possible - and the one with the most is the most productive".  That is not how basketball works. You do what your team requires of you to win, and if you are successful, the whole team benefits.

And some of you might say, "what about plus/minus?".  But there are problems with that approach, too, which you can google for yourself.

OK, so this is all very incomplete, I realize that - this is only one blog post. Basically, as of today, take a looking at how a player affects his teams' aggregate stats is a lot more valid than looking at a player's individual stats.

Or, we can throw this all out the window and go with Kobe and Phil's explanation that if the team does well without you, it's "invisible leadership"!

Anyway, the whole impetus of this was trying to figure out if the Lakers shot any better when Kobe left, since some would think the others would fill in the vacuum at their normal FG%s, but that doesn't seem to be true.

The point is to discuss - have at it in the comments section.