It’s the holiday season which means it’s the time of year when everyone is in an especially giving mood. Maybe you give an extra tip to the Starbucks barista, drop change in the Salvation Army bucket, volunteer at a shelter, bake cookies for the mailman, or buy a gift for that family member you’ve been avoiding all year. If you’re the general manager of a baseball team, you might even choose to give away a star player to a hated opponent. December is one of the most active trading months in major league baseball, and it’s littered with examples of uneven trades that altered the direction of both franchises involved.