Umpires are human, and prone to mistakes, (except for Bretman, ofcourse). I've seen umpires (rarely) with a strike zone of anything above the waste to the bottom of the chin. A pitchers nightmare and a hitters delight. But most, from my experience call a low zone, as low as shoe laces. Pitchers and batters need to adjust. When you come across that good umpire, which I believe are most, don't bash them over a borderline strike, but lavish them with praise because lets face it, their job isn't the easiest or for that matter the most desirable.