The best example of this sort of thing happening is in Professional bowling. In 1974, Don McCune won 6 titles and player of the year. However, rather than keep a secret, he told everyone how he did it. The plastic bowling balls of the time hooked based on how soft the coverstock was. He found a chemical he could soak the balls in to soften the coverstock significantly, giving him a huge advantage over the other players. Everyone started doing it, then the hammer came down. The USBC (maybe the ABC, I'm not sure) came out with rules regarding the hardness of a bowling ball. The "Soaker," (as it was called) was no longer usable in sanctioned competition. If Don had kept his mouth shut, he could have dominated the tour for 8-10 more years!