Defining the Strike Zone

Can batters define their own strike zones? There is conjecture that umpires will tend to call pitches strikes in locations where batters swing, and balls in locations where batters don't swing.  That may be the case for Jim Thome.  Over the last three season, Jim walked in 16% of his plate appearances, the third highest in the major leagues behind Chipper Jones and Jack Cust (minimum 1300 PA).  So Jim knows when to swing and when to take. The following heat map shows where Jim swings at pitches:

Jim Thome swings, 2008-2010Note that Thome swings less when the pitches are at the top and bottom edge of the strike zone, and more when the pitches are on the insdie and outside corners.  Compare that to where the umpires call balls:

Jim Thome called balls, 2008-2010While not exactly the same, the umpires are giving Jim the benefit of the doubt up and down, where he swings less, but they are penalizing him on the outside corner, where he swings more.  There may be something to batter swings influencing umpires after all.