Malcolm Gladwell has more on the need to analyze the validity of sports records (cf. Bonds) before accepting them. An excerpt:
Second–and here I strongly disagree with some readers–peformance enhancing drugs work. They confer an enormous advantage. They allow an athlete to train so much harder than he or she otherwise could that they can turn mediocre athletes into very good athletes, and very good athletes into legends. “Game of Shadows” makes, I think, an overwhelming case that drugs allowed Bonds to essentially double his annual home run output, and turned Tim Montomgery from an also-ran into a world record holder.