In the latest issue of The National Pastime, Lyle Spatz describes candidates for the worst and best trades in St. Louis Cardinals history. I decided to apply Win Shares to the trades, as one way of measuring which deals were best and which were worst. Obviously, the Win Shares for the players involved in the trade were part of the equation. However, I also included Win Shares for any players the "deal players" were subsequently dealt for. Also, when those deal players were subsequently dealt, there were other players sometimes thrown in who went with them. I treated those throw-ins, who otherwise would not have had a connection to the deal (some of whom were quite good), as "opportunity costs," so their future Win Shares were subtracted from the team that traded them away because those were Win Shares the trading team would have had if not for the throw in.
As a brief example, Rick Wise came to the Cards when they traded Steve Carlton to Philadelphia. St. Louis gets Wise's WS in a Cards uniform. Philadelphia gets Carlton's WS in a Phils uniform. Wise was then traded to Boston for Reggie Smith and Ken Tatum. St. Louis gets Smith and Tatum's WS in a Cards uniform. But in that deal Bernie Carbo was sent from the Cards to Boston. Carbo is the "throw in" player otherwise unconnected to the original trade. Since the Cards lost the future value of his services, Carbo's WS after the trade are subtracted from the Cards side of the ledger, because they lost his future services. In some cases, this goes on and on. One note, though: the opportunity cost of trading away players actually connected with the deal -- like Wise, or Reggie Smith after he was traded to the Dodgers -- was not factored in, both for reasons of complexity and because there seemed to be a danger of double-counting...my brain got a little twisted up trying to figure it out.
It goes without saying that other things factor into trades. Clubhouse personality, the availability of someone in the minors to replace the traded player, etc. I'm not saying the method is perfect...it's just the way I chose to do it because I think it is interesting.
I'll break this into two more posts. One for the worst trades, and one for the best (from the Cards perspective).
