The called strike seems like such a fundamental part of baseball, that it's hard to imagine a time when it didn't exist. But the early game that evolved from rounders and other ball-and-stick sports gave significant advantage to the batter. Pitchers not only threw underhand -- more about that on the next page -- but batters could sit back and wait for their perfect pitch before even attempting a swing. Apparently this bored the knickers off of enough players and spectators that the called strike was among the new rules passed at the First Base Ball Convention in 1858 [source: Miklich].
But even the called strike came with some generous caveats. For example, an umpire couldn't just call out "strike" at the first good-looking pitch. He would issue a warning first. Perhaps something like, "Pardon me for intruding, my good man, but that last one looked rather on target, if you ask me. Consider thyself under advisement that I will feel it necessary to call a similar pitch as a strike, of which you get three. Fair enough?" Even more gentlemanly, the umpire was prohibited from calling a strike on the very first pitch, unless the batter swung and missed [source: Miklich].
To add to the absurdity, all the way until 1886 batters could "call" their pitch [source: Miklich]. Before stepping into the batter's box, the batter would ask the pitcher for either a "high ball" or a "low ball." To qualify as a strike, a high ball needed to be both over the plate and between the batter's waist and shoulders. A low ball needed to pass over the plate between the batter's knees and waist. The batter had to choose one or the other and couldn't change his mind during the middle of his turn at bat.
In 1887, the high and low strike zones were combined into a single zone that extended from knees to shoulders. The strike zone has undergone several alterations in the ensuing years. Currently, the official MLB rules position the top of the strike zone at halfway between the top of the shoulders and the waist of the uniform. The bottom of the strike zone is not the knees (because that would be too normal), but the "hollow beneath the knee cap," aka the knee pit [source: MLB.com].