Thursday, April 09, 2009

In the opening round of the Masters golf tournament earlier today, Chad Campbell set a tournament record by getting a birdie on the first five holes.

UPDATE: To probe a little more into Campbell's opening-round performance, I decided to estimate the probability of his five straight birdies (assuming that he's a typical golfer). A total of 96 golfers began play. For each of the holes in Round 1 -- including the first five, which were of primary interest -- the number of golfers who broke par (most frequently by birdie, but also occasionally by eagle) is available here. The numbers of par-busters for each hole, which when divided by 96 yields a probability of breaking par, are as follows:

Hole..........Par-Busters..........Probability

1.............7 (all birdie)............07

2.............46 (incl. 2 eagles).......48

3.............30 (incl. 1 eagle)........31

4.............4 (all birdie)............04

5.............11 (all birdie)...........11

Multiplying these probabilities together yields roughly .00005, which is 5-in-100,000 or 1-in-20,000.

Some cautions must attach to this probability. First, it was a post-hoc decision to calculate it. To paraphrase a warning I once received from a prominent statistician, no one presumably was asking before the tournament, "What are the odds that Chad Campbell is going to birdie his first five holes?" The very unusualness of the accomplishment is what prompted me to analyze it.

Second, even if we accept the 1-in-20,000 probability, with large numbers of professional golfers playing large numbers of holes in large numbers of tournaments, the feat of five straight birdies is one that may be expected to occur every so often.

1 comment:

Mike Knobler said...

I see you are aware of the so-called "clustering illusion," in which an observer infers that a cluster of events seemingly could not be random. That 1-in-20,000 calculation would be the odds of that golfer breaking par on those five holes, and you selected the golfer and the holes only in retrospect.

Have you read the "hot hand" studies of free throw shooting and what if any information we can deduce about the odds of a shooter making his next free throw from the information of whether he made his previous one?