Michael Bourn is one of the more coveted free agents on the market this winter.

He may not have the power that guys like Ryan Braun and Jose Bautista possess, but he still made the list of most productive outfielders over the last four years.

Here are the top five outfielders in terms of WARP over that period:

1. Ryan Braun, 25.9
2. Jose Bautista, 20.2
3. Michael Bourn, 19.0
4. Matt Holliday, 18.3
5. Andrew McCutchen, 18.1