ne of the cardinal rules of horse racing is that betting on favorites is fun — who doesn’t like having a winning ticket? — but it’s the quickest way to go broke. Except, that is, in the most famous race in America.

The Kentucky Derby should be nearly impossible to handicap. The horses, at just 3 years old, don’t have much experience and are still maturing. Many of them have never run this distance before, or run at Churchill Downs. And even if a handicapper can sift through all that uncertainty and use a combination of past performances and pedigree to identify the best contenders, it can all become irrelevant thanks to the abnormally large Derby field — with as many as 20 horses creating gridlock and chaos, results ought to be utterly unpredictable.

That’s what makes the last several years of the Kentucky Derby so strange: It is, seemingly, getting more predictable. For four straight years, the favorite has come out on top. It began with Orb in 2013, then continued with California Chrome, American Pharoah and Nyquist.

In total, 16 favorites have won the Kentucky Derby in the last 50 years.1 And that has produced a compelling betting strategy: Forget all the wonky handicapping. Over the last half-century, placing a $2 bet (the smallest bet you can make on a single horse in the Derby these days) on the favorite each year would have netted you $107.80 on a $100 investment — a 7.8 percent profit. But in just the last 20 years, returns on that same strategy would be much better: 74 percent.