Used as a noun ("You're in the big leagues now") or an adjective ("big-league lawyer").
Literally, Major League Baseball, first use dating back to 1899.
At one time, there were seats where the black area is now, but because of distractions the seats were removed and the area painted black. In baseball, someone with a batting average of one thousand (written as 1.000) has had a hit for every at bat in the relevant time period (e.g. A perfect batting average would be 1.000 (read: "one thousand").
A batting average of .300 ("three hundred") is considered to be excellent, which means that the best hitters fail to get a hit in 70% of their at-bats.
The rules specify which pitching movements are illegal.
The spirit of a balk is that certain movements mean that the pitcher has begun the pitch, so the runner cannot then be picked off.
A breaking pitch, usually a slider or cut fastball that, due to its lateral motion, passes through a small part of the strike zone away from the hitter after appearing it would miss the plate entirely.
While the first two examples are analogues to bailing out of a plane via parachute, the last one is akin to bailing out a boat that's on the verge of being swamped, or perhaps bailing somebody who is in trouble out of jail.
Goldberg, "Long Island Vines; Macari Price: .5 Million", The New York Times, 18 July 2004In sabermetrics, "ball in play" and "batting average on balls in play" (BABIP) have specific technical definitions that are used to determine pitchers' ability independently of the fielding defense of a team. A short downward swing intended to make the ball rebound off home plate or the packed dirt immediately in front of the plate.
In this definition, a home run is not a ball in play. The goal is to produce a bounce high enough so that, even if the ball can be fielded by an infielder the batter will reach first for a base hit.
The original x86 hardware execution mechanism wasn't in the ballpark.