Baseball
The most important part of the game is between the pitcher and the batter. The pitcher throws, or pitches, the ball towards home plate. The pitcher normally throws the ball close enough for the batter to hit it. If the pitcher throws the ball in the strike zone, which is the area  over home plate and between the hitter's knee and chest, the pitch is a "strike", unless the batter hits the ball. The pitch is always a strike, regardless of where it is, if the batter swings the bat and misses, so the batter must have good aim with the bat. Three strikes are a "strikeout", and this is one way to make an "out". A pitch that the batter does not swing at, and which is not called a strike, is a "ball." On the fourth "ball" thrown by a pitcher, the batter "walks" to first base, so it is important to pitch well.