Stories like this one suggest that winning Olympic gold in Beijing have catapulted team members into better seasons. Here’s a quote from Lebron James:
“To win the gold just uplifted all of us into this season. A lot of people were wondering if we’d hit a wall because we played in the Olympics. But look at everybody from the Olympic team. Everybody is playing the best they’ve ever played.”
But are they really? I’ve heard claims like this about the Gold medal winning Beijing squad in the popular sports media as well. And this is a debate that comes up every four years when coaches and owners express concern over their players, in whom they have sunk subtantial investments, play international ball and expose themselves to the risk of injury instead of recovering during the offseason. Mark Cuban of the Mavericks and the L.A. Lakers’ head coach Phil Jackson have led the charge on this front (see, e.g. this column by Michael Wilbon) arguing that NBA player participation in the Olympics results in wear and tear on players, more injuries, and poor performance in subsequent seasons.
So which is it? Here is a little blog-level casual empiricism. I had an RA do some digging comparing the performance of Olympic team members in the seasons before and after the Gold medal winning 2008 Olympics and the disappointing 2004 team which took home the Bronze medal (losing to Puerto Rico, Lithuania, and Argentina). Obviously, we only have partial results for the current season which is not quite to its halfway point yet. We also excluded Emeka Okafor from the 2004 group since he was a collegiate athlete at the time of the Olympics and had no “before” NBA stats. Like I said, this is casual empiricism. Further, the 2004 Olympic team might not be the best control group available, e.g. a group that participating in the Olympics but did not win the Gold. Maybe a better control group would be the pre- and post- performances of players that were on the margin but were not ultimately selected to the Olympic team and therefore did not receive the “Gold medal” treatment. On top of that, maybe there are other measures one might want to look at other than points, assists, rebounds and steals, e.g. measures of team success, measures of success down the stretch when Olympians might be wearing down, controlling for difference in ages of the various teams, movements from team to team, etc.
With those caveats behind us … what did we find?
Check out the chart below the fold.
Interestingly, a simple means comparisons reveals that the impact of winning on performance is not noticeably better in any of the categories. We calculate the differences between pre- and post Olympic performances for the Bronze medal squad, the Gold medal squad, and then the difference between the two (the “difference in difference” row). The first thing to notice is that, at least by these measures, there just isn’t much evidence that the Beijing Gold Medalists have parlayed that success into success on the court. Indeed, the difference in difference calculations suggest that the ultimate Olympic success might have a negative impact on subsequent year performance. In any event, this casual analysis suggests that perhaps Lebron is wrong. The Beijing Gold medalists not only aren’t playing better by any of these objective measures, but are worse off in the post-Olympic season relative to the Bronze medalists.
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|
|
Points |
Assists |
Rebounds |
Shooting % |
Steals |
| 2003/04 |
19.79 |
4.18 |
7.27 |
0.45 |
1.42 |
| 2004/05 |
22.46 |
4.67 |
7.74 |
0.48 |
1.35 |
| Difference |
2.67 |
0.49 |
0.47 |
0.02 |
-0.07 |
|
|
|
|
|
|
|
| 2007/08 |
21.61 |
5.72 |
6.90 |
0.48 |
1.38 |
| 2008/09 |
20.38 |
5.26 |
7.09 |
0.47 |
0.81 |
| Difference |
-1.23 |
-0.46 |
0.19 |
-0.01 |
-0.57 |
|
|
|
|
|
|
|
| Difference in Difference |
-3.90 |
-0.95 |
-0.28 |
-0.03 |
-0.5 |