Your criteria is flawed honestly. What does it matter whether they stayed on the same team? The A's were a lousy team so they traded Street. Do you expect the White Sox to be lousy? With starters going less deep into games and the way relievers are used in the playoffs, keeping them the extra year is helpful. Saying "the extra year of control doesn't matter" is ridiculous. 6 is more than 5. It is really that simple. If he is a stud, would you want him an extra year?