How many points is the spread in dog years?

A few decades ago, the expertise of so-called Wall Street wizards was effectively debunked by the "random walk" theory, which proved that over the long haul, the so-called experts were no better than chance, and that a portfolio based on throwing darts at the stock listings would perform as well as one picked by a bunch of expensive analysts.

My local newspaper has applied this theory to the sports pages, with predictable results. Every week, its four sports columnists make public their picks for the coming NFL games. They match wits against a dog. Two of the humans have identical winning percentages of 51.8%. One is at 46.4%. The laggard comes in at 42.7%. The dog? Comes in 3rd out of the five at 48.2%.

Do you choose to conclude that here, as on the Street, expertise is meaningless? OK. That once the appropriate spread is factored in, sports betting becomes purely random? Fine. That dogs might make good sports writers? No objections here.