Major League Baseball umpires miss 20 percent of close calls, according to "Outside The Lines" survey - ESPN I was wondering if anyone would actually do a study of "missed" calls. I don't think that the sample size is big enough to do more than provide a picture of just how inaccurate calls of the field can be. I fully agree that a booth replay is necessary. They should add one, maybe two more umpires to the staff. For all questioned calls (maybe a limit of 3-5 a game; that would depend on how long it took to review calls) the booth would signal/call down the proper call after checking the slow-mo replays. I don't support replay for balls/strikes.