Anytime I have a game circled and it's the first game of the series I wait to see who the umpire is this time of year...I mainly do this to make sure I don't have an over ump with one of my unders and vice versa for over games...I also have a list of what I consider extreme over/under umpires, I will reanalyze those games when it's one of those umpires to see if the pitcher/teams match up for that particular game...I really don't start using umpires until after the Allstar break when I feel they have had enough games under their belt behind the plate for that season...as the season wears on I value the umpire involved more and more...if my experience as a professional (player and coach)taught me anything is that the guys behind the plate matter a great deal in how we would come up with our gameplan of how to pitch that particular day...same goes for me now when I place wagers...hope this helps