Traditionally, I like to start my preview series each spring with a defensive-focused piece that becomes the centerpiece of the logic-based previews that are to follow. You can check the archives and see the 2012 Detroit Tigers preview and the 2013 Los Angeles Angels preview for examples. In them, I talk about my theory that projecting and even grading team defenses is far different than a mere sum-of-the-parts exercise (’12 Tigers essay) and how the dreaded ‘eye test’ may be responsible for a significant amount of distortion in the Total Zone and Ultimate Zone Rating systems that form the backbone for the defensive portion of differing WAR calculations (’13 Angels).