Barry Bonds is also an excellent example of this, as was discussed above. However, also as mentioned above, there is a difference between being aggressive and being a hacker. Vlad Guerrero is also a good example of this. Despite his reputation, Guerrero has a career IsoD of .066. He takes his swings, but he also has a good enough eye that is he is willing to let bad pitches go by and take walks. My primary concern with Vitters and the Cubs' approach to him is based on this issue. In the time I have been following prospects with great interests, I find that a player developing good plate patience later in his career tends to be the exception more than the norm. That may be an incorrect perception on my part, but I worry that, with someone like Vitters, he will develop bad habits as a result of this emphasis on aggression and that he will not be able to develop plate discipline in the way he should. That may not be the case, but I will be concerned if, next season, he does not post decent walk numbers.