An engineer, a mathematician, and a physicist went to the races one
Saturday and laid their money down. Commiserating in the bar after
the race, the engineer says, "I don't understand why I lost all my
money. I measured all the horses and calculated their strength and
mechanical advantage and figured out how fast they could run..."
The physicist interrupted him: "...but you didn't take individual
variations into account. I did a statistical analysis of their
previous performances and bet on the horses with the highest
probability of winning..."
"...so if you're so hot why are you broke?" asked the engineer. But
before the argument can grow, the mathematician takes out his pipe and
they get a glimpse of his well-fattened wallet. Obviously here was a
man who knows something about horses. They both demanded to know his
secret.
"Well," he says, between puffs on the pipe, "first I assumed all the
horses were identical and spherical..."