why is there a pitcher's mound?

Answer 1

Craig S is only partly right. The year Bob Gibson had his great season was the only year the mound was 15-inches. It was lowered "back" to 10-inches the following year.
As far as the mound goes, in 1893 when the pitching distance was moved from 50-feet (when pitchers threw under-handed) to 60-feet 6-inches (now over-handed) it was not to give the pitcher an advantage... but rather to compensate for the extra 10 1/2 feet and (believe it or not) to save wear and tear on his arm.
This is one of my pet peeves about pitching records. Most record books say "since 1900"... when it should read "since 1893" which is when as stated... the mound went to 60' 6".

Answer 2

It exists to give the pitcher the advantage of throwing "downhill," which is why it only came into being after baseball began allowing overhand pitching.

When pitchers threw underhand, they threw from a "pitcher's box," which was a flat surface. Once they changed to overhand pitching, pitchers and groundskeepers started to pile dirt within this box. Eventually, in 1904, the rules committee caved in and put into the books the 15" mound rule. It would stay at that height until after Bob Gibson's awesome 1968 season - the year of no offense - when they lowered it to 10 inches.

Edit - I respectfully disagree with the answer below mine. The mound was NOT changed before the 1968 season - that's according not only to me, but to both Baseball Reference and Baseball Almanac:

http://www.baseball-reference.com/bullpen/Pitcher's_mound

http://www.baseball-almanac.com/rulechng.shtml

Answer 3

because the height gives the pitcher an advantage

Answer 4

I don't know. Why is there a back board on a rim?

Answer 5

mortars