Jack,
I would suspect that the only 'system' he has is not very 'scientific', or so he seems to be saying when he wrote:
"My (John Garrity) Top 50 is above politics, incorruptible, and as close to scientific perfection as chaos theory and a writer's budget will allow. My system utilizes a complex web of informants and busybodies who file detailed reports on everything from flagstick heights to ball-washer detergent quality. This data is augmented by public records and, when necessary, unauthorized credit checks. Then I thoroughly Google the course in question.
Finally, we do the math. I say "we" because the Top 50 employs a secret algorithm developed by professor Charles Eppes at the California Institute of Science. I don't claim to understand how this algorithm works — it covers five blackboards in Charlie's garage — but it took the processing power of a dozen Mac G-5s, working through the night, to produce the final list.