But absent a reliable test, it's not easy to catch hormone hounds. Even a blood test may not suffice. The World Anti-Doping Agency (WADA), which supervises testing of Olympic competitors, has screened 8,500 athletes for HGH since 2000. And how many positive results has it gotten? Zero. So anyone feeling puny and weak without steroids is bound to contemplate a switch.

We also know baseball's new testing regime has not miraculously dried up the demand for performance enhancers. After Major League Baseball outlawed amphetamines, an interesting thing happened: More than 100 players got "therapeutic exemptions" for banned stimulants to treat Attention Deficit Disorder.

Calling that number "incredible," Dr. Gary Wadler, a WADA official, told USA Today, "There seems to be an epidemic of ADD in major-league baseball."

For now, though, the broadest boulevard for cheating is HGH. That could change: At a recent conference sponsored by Major League Baseball at the University of California, Los Angeles, scientists said they were making progress toward a urine test for the agent. But it is still in the future, leaving dishonest players ample opportunity.

We may have banished steroids, but there is no reason to think baseball is any cleaner now than it was before. If and when an HGH test is developed, we are likely to get another round of failed drug tests. And one or more of today's stars is bound to be doing the confession-and-repentance routine.

Unfortunately, we won't know how bad things were back in 2009. In theory, current samples could be preserved and retested in the future. But Major League Baseball doesn't preserve samples. That means today's players -- possibly including the supposedly repentant Rodriguez -- can use HGH with little fear of someday being unmasked.

It's slightly comforting to think we have moved beyond the steroid decade. But the drug-free era hasn't begun, and it may never.