Very interesting study David, but do you think a contributing factor to the decline in percentage of players under 5'9" is due to the entire human race evolving and growing taller, and the mixing in of different races of players? For example, average human male height in the UK has gone up in the 80 years in your study.

Hazey,

I'm sure that has something to do with it, but the dramatic drop from 1926 to 1939 doesn't really fit with that.