Larry Bird and the Dangers of Metrics


After re-reading Paul’s article on Steve Nash’s phenomenal shooting percentages (read it), I wanted to take a look at how truly great shooters stack up at truly great scorers. What I found was that efficient shooting is not as important to PER as I expected.

I ran a list of player seasons for players who averaged better than 25 points per game while shooting at least 50% from the field and 35% from behind the 3 point line. It was only achieved 11 times. 3 of those were Larry Bird. 3 were Chris Mullin. Dale Ellis accounted for 2.

Click here for the full list with complete per game statistics and PER.

Isn’t it odd that Larry Bird can shoot 2% better than LeBron James from the floor including 5% better from the three point line and shoot 14% better from the free throw line to boot while scoring the same amount of points with offsetting assists, rebounds, steals, and blocks, fewer turnovers, and doing all of it in the same amount of minutes per game and yet his PER is 3 points lower?

Here’s the same list of player seasons with advanced stats.

The Metrics Generation

There are two factors at work here. 1st, and probably the more significant of the 2, is the difference in free throw attempts. LeBron is currently getting to the line more than 10 times per game. Is it worth going into the details regarding the change that the handcheck rule has had on the game again? Probably, but fortunately we’ve already covered that here. I do want to note that LeBron is going to the line 10 times per game while taking 5 threes per game. This is largely a post-rule change phenomenon. It’s happened 10 times, all after 2000, all but 2 after the 2004 no handcheck rule went into effect. You can see the effect in the True Shooting Percent (TS%) on the advanced stats spreadsheet. LeBron’s TS% is higher than Larry’s and higher than Michael Jordan’s even though they both shot better than him from the field, the three point line, and the foul line, because he’s able to get to the line more often. LeBron’s aggressiveness coupled with defenders’ inability to do anything to slow him down makes up the difference in shooting percentages.

The other factor is of course the pace / usage issue. Bird played in a faster era, so he had more possessions per game to manufacture scoring attempts, though clearly LeBron uses far more. Metrics like PER get very happy when an efficient scorer like Shaq, Jordan, or LeBron uses a ton of possession (like Shaq, Jordan, or LeBron do). And logically that works. If you’ve got a guy who scores at a high percentage, why put the ball in anybody else’s hands?

Actually there are two connected reasons, and they undermine possession-based metrics that love usage in round-about ways. First you’ve got the concept of diminishing returns which basically says that the more a player’s usage increases, the more likely his efficiency is to decrease. I’m not 100% sure this is true, but it follows logically that at a certain point the load will become too much for one individual, and he won’t be able to win by himself. It happened to Jordan against the Pistons who basically baited him into trying to beat them one on five, and it happened to LeBron against the Celtics in ’08 when they did the same thing. The other effect of one player taking all the responsibility for putting the ball in the basket is that he’s not getting anything out of his teammates. Sure that’s an exaggeration, but on a continuum, how much do you want to empower one man while disenfranchising 11 others?The "What's a Metric?" Generation

Here’s where I think guys like Bird and Isiah Thomas get lower rankings from metric-lovers than they probably deserve. Their teammates were good enough that it made sense for their usage rates to suffer in order to keep their talented teammates involved, motivated, and dangerous to the opposition. Could Isiah beat his man to the hoop and draw fouls on the offense a lot more often? Could he operate in the system used by Deron Williams or Chris Paul? Sure. But Mark Aguirre, Joe Dumars, and Vinnie Johnson wouldn’t get to isolate and score on those possessions. Their defenders would not be in jeopardy. They weren’t really spot up shooters (well, Joe could do that). They weren’t really running wing scorers. To be effective, they needed Isiah to let them play their games. He had to sacrifice. And he did. And it worked. Bird was in much the same position with McHale and Parish on the blocks. He had to sacrifice his post scoring opportunities so that his less versatile teammates could produce. And it worked. If ain’t broke…


3 Responses to “Larry Bird and the Dangers of Metrics”

  1. pmadavi Says:

    I know I’m not supposed to wax on our own site, but damn J, this is some good analysis.

  2. jpalumbo Says:

    Praise from Caesar!

  3. G.O.A.T. – The Limitations of Rankings « Double Dribble Says:

    […] Which brings us back to the commentator’s point regarding Bird being more valuable than Jordan. Sometimes what a player doesn’t do is as important as what he does and behind the scenes factors have a bigger impact on winning than an individual’s statistical production. I made this very point using Larry Bird (and towards the end Isiah Thomas) not very long ago in this post. […]

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