In a nation committed to better living through chemistry - where Viagra-enabled men pursue silicone-contoured women - the national pastime has a problem of illicit chemical enhancement. Steroids threaten the health of the 5 percent to 7 percent of players proved, by a mild regime of scheduled tests, to be using them. Steroids also endanger emulative young people. Further, steroids subvert what baseball is selling - fair competition. And they strike at the pleasure of engagement with America's team sport with the longest history.