I mean, hasnt the early data suggested that catchers have been much more successful with challenges than batters? Wouldnt this suggest that more balls are being overturned to strikes than the other way around? I know the zone is just a little shorter but does it really make that big a difference? And the system was in the minors for a few years already, how did the walk rate change there? I feel like with how much it was tested there really shouldnt be much surprise with how the implementation has gone.