Beginning of each inning.

I was looking for the rule that might indicate whether a pitcher may be replaced before completing his pitching to a batter.  My idea is to have two pitchers on the mound alternate from pitch to pitch as they see fit, though not necessarily on each pitch.  Anyway, I stumbled onto a paragraph with stuff I had not realized.

http://mlb.mlb.com/mlb/downloads/y2011/Official_Baseball_Rules.pdf


8.03 When a pitcher takes his position at the beginning of each inning, or when he
relieves another pitcher, he shall be permitted to pitch not to exceed eight preparatory
pitches to his catcher during which play shall be suspended. A league by its own action
may limit the number of preparatory pitches to less than eight preparatory pitches. Such
preparatory pitches shall not consume more than one minute of time. If a sudden
emergency causes a pitcher to be summoned into the game without any opportunity to warm
up, the umpire-in-chief shall allow him as many pitches as the umpire deems necessary.
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1. "eight preparatory pitches ... not ... more than one minute of time"  Wow.  One minute?  Who knew?


2. "emergency ... as many pitches as the umpire deems necessary"  Announcers always state that the new pitcher gets as many pitches as he needs to warm up, not as many as the umpire allows.