I know the Sox used it. They copied it from the A's! Couldn't find their own secret for success so they stole someone else's. They tried to steal the GM too. Otherwise they would be pushing a Century without a WS win.
Well, buy a clue. It wasn't the A's system either. A guy named Bill James developed it. And since the Red Sox were smart enough to hire Bill James to implement it, I'd hardly call that stealing. I'd call it a smart move. But then again, we're probably talking to a 12 year old who steals candy bars from the convenience store and sees it as "borrowing."