Here is an excerpt from, which describes a new research study investigating whether other golfers do worse when Tiger Woods plays:

Tiger is thus formidable even if he doesn’t always take first, which gets us to the study’s question: How does his participation in a tournament affect other players’ performance? It’s almost a given that other players will rank lower when Tiger gets first place, but what the study asks is whether other players shoot more strokes on a given course when Tiger’s in the mix.

Analyzing data from round-by-round scores from all PGA tournaments between 2002 and 2006 (over 20,000 player-rounds of golf), Brown finds that competitors fare less well—about an extra stroke per tournament—when Tiger is playing. How can we be sure this is because of Tiger? A few features of the findings lend them plausibility. The effect is stronger for the better, “exempt” players than for the nonexempt players, who have almost no chance of beating Tiger anyway. (Tiger’s presence doesn’t mean much to you if the best you can reasonably expect to finish is about 35th—there’s not much difference between the prize for 35th and 36th place.) The effect is also stronger during Tiger’s hot streaks, when his competitors’ prospects are more clearly dimmed. When Tiger is on, his competitors’ scores were elevated by nearly two strokes when he entered a tournament. And the converse is also true: During Tiger’s well-publicized slump of 2003 and 2004, when he went winless in major events, exempt competitors’ scores were unaffected by Tiger’s presence.