If there are runners on base, it's a balk. Runners advance one base (MLB Rule 8.05(e)). If there's no one on base, and the pitch is delivered, a ball is called unless the batter reaches base otherwise (MLB Rule 8.01(d)).
Yes, there is no restriction on changing pitchers during an at bat, unless the current pitcher just entered the game and the batter is the first batter he faces. The pitcher must face at least one batter before he can be replaced, unless the pitcher is injured, or ejected from the game.
i think it was the 3rd inning Relief pitchers have, on occasion, replaced starting pitchers before the latter has gotten a single batter out. Sometimes the starter just has a REALLY bad day.
Yes--there's no limit to how many players can be substituted at once. Also, in the National League (or any league where pitchers have to bat) a team can make a "double switch", which in the case of a pitcher and catcher would result in the new pitcher batting in the previous catcher's spot in the batting order, and the new catcher in the pitcher's spot (probably ninth).
Yes, before 1883, a pitcher could not deliver a pitch above his waist.
They look at the pitchers
A pitcher can be changed during an at bat as long as that pitcher has pitched a full at bat to at least one batter. A pitcher may not be brought into a game and then taken out before pitching one full at bat unless he suffers an injury which the umpires deem serious enough to require off field attention.
I believe Red Faber was the last. He pitched for the White Sox here is the answer i got when searching for this answer: The last LEGAL spitball win? Pittsburgh Pirates' pitcher Burleigh Grimes on September 10, 1934, who appeared in relief and defeated the New York Giants 9-7.
Absolutely not. A ball that gets dirt on it is unusable because the dirt affects the shape of the ball, which can make it fly differently when pitched. This is also why pitchers aren't allowed to put any foreign substance, such as Vaseline, on the ball before pitching.
It was a long time before women were allowed to fight in battles. Molly Pitchers is a nickname for the woman who fought in the American Battle of Monmouth.