Bay. He is a superior hitter with a career ops over .900. Wells is a mediocre fantasy outfielder. He does typically do better in the second half, so he should be a viable option in a fantasy outfield, but he is a far inferior hitter (Wells's ops in his career year is lower than Bay's career ops). I think these two are closer in a 5x5 fantasy format than they are in the mlb, but Bay still has a substantial edge. He is looking like he may become the Pirates' perennial allstar.