Being outdoors frequently provides exposure to sunlight which produces Vitamin D, a potent steroid hormone. This may also be a factor in the south's advantage in golf. The correlation between population adjusted number of top pro golfers and the UV Index in their birth states is similar to what we found for top (Division 1A) college football players (see Football’s Southern Exposure). However in terms of sheer numbers, top pro golfers are relatively few and far between averaging roughly 1 or 2 pros per 10 million in population.
Using the Wikipedia data, we determined the birth state of the (American born) PGA Tour Pro(s) with the most wins in each season since 1960. There were 38 unique winners (with ties) and each golfer was counted only once if they were multiple year winners. The golfers were each placed into one of seven groups by yearly average UV Index range in their birth state (<5.25; 5.25-5.74; 5.75-6.24; 6.25-6.74; 6.75-7.24; 7.25-7.74; and >=7.75). The total number of golfers in each group was divided by the total population of all states in each group.
Figure 1 illustrates the correlation (R-squared = .56) between the number of US golfers per 10 million population their birth state average UV Index. Big states such as Texas, California and Florida were divided into separate regions since the UV Index varied significantly within the state. For example the UVI in Southern California (LAX) is 7.61versus 6.31 in the San Francisco area. Population was equally divided in each region of the state. The tilt in the linear fit toward the high UV Index states is statistically significant (p = .04).
Figure 1. High UV Index States Produce Significantly More Top PGA Tour Winners.
Correlation is no proof of cause and it's impossible to tell how much of a factor (if any) sunshine and Vitamin D are in shaping a young golfer's chances of future success. Even those in the south face long odds of being a top PGA Tour pro. However, most of us would be happy enough with shaving a few strokes off our handicaps. Even with this modest goal there's no way to be sure if lessons, new equipment or other tips are making a difference. However there seems to be little downside in supplementing one's diet with more Vitamin D in the north, particularly in the winter months when the UV Index can be very low.
|UV Index||Birth State||PGA Tour Pro|
|8.39||Texas (DFW)||Brooks, Magee, Kite, Travino|
|8.02||Florida (JAX)||Duval, McCumber|
|7.95||Texas (HOU)||Rogers, Crenshaw|
|7.61||California (LAX)||Woods, Mickleson, Pavin, Stadler, Casper|
|6.70||North Carolina||Love III, Floyd|
|6.31||California (SFO)||Miller, Lema|
|5.52||New York (JFK)|
|5.34||Ohio||Cook, Watson, Nicklaus|
|5.01||New York (BUF)||Levi|