well there was an investigator who said he believed if he had more time he could've proven that rose bet against the reds, but that's not really evidence. it's known he bet ON them almost every game when he managed for them, he was a gambling addict. some people say that the fact that he didn't place bets on 4 games one year could be construed as he was signaling to the gambling community not to bet on those games also, and was rigging them, and they did lose those games, or that he knew he was going to use some less good pitchers on those games and save them for more important games. which means he gambled with insider knowledge. it's obviously bad for the sport and perhaps his gambling did affect his decisions while managing but there's never been any solid proof of outright rigging a game or even actually just betting against them.