Fair Ball - A ball that is hit by the offensive player in fair territory. If a ball crosses past first base or third base in fair territory and then rolls into foul territory, it is considered a fair ball.

Fair Territory - The area on the baseball field that is formed by the angle of 90 degrees between third base, home plate, and first base. All other areas are considered to be foul territory with the exceptions of the area beyond the outfield wall.

Fast Ball - A ball thrown at high velocity by the pitcher. The fast ball is the pitch that is easiest for the pitcher to control the location of. It is often used when the pitcher needs to throw a strike such as counts of 3-0, 3-1, and 2-0.

Field - See baseball field.

Fielder - A defensive player.

Fielding Percentage - The statistical information on a defensive player that reflects the fielder's ability to catch balls without errors. Also known as a fielding average.

First Base - The base on the field that is the 1st in the series of bases that an offensive player must traverse to score a run. It is guarded by the first baseman.

First Baseman - The defensive position located at the right side of the infield between the second baseman and the foul line.

Fly Ball - A ball that is hit with altitude by the offensive player and is the opposite of a ground ball.

Fly Out - An out made by the defensive player when the fielder catches the ball before it touches the ground.

Force Play - An defensive play where the lead runner is thrown out. If the second runner is thrown out before the lead runner, then the force play is removed from the lead runner. In the case of the removal of the force play on the lead runner, the defensive team must tag the lead offensive runner to make the out.

Forfeited Game - A game in which the umpire disqualifies one time for an infraction of the rules of baseball. In the event of a forfeit, the team not in violation is awarded a score of 9 and the violating team is awarded a score of 0 by the umpire.

Fork Ball - A pitch thrown by the pitcher that sinks. Also known as a split-finger fast ball.

Foul Ball - A ball batted by an offensive player that is hit into an area other than fair territory. If a defensive player catches the ball in foul territory before it touches the ground then the offensive player is out. If the ball hit by the offensive player is not caught by the defensive player then it is called a strike by the umpire if there is less than two strikes on the offensive batter.

Foul Line - A chalked line that seperates fair territory from foul territory. The right foul line begins at home plate and continues to first base and then to the outfield wall. The left foul line begins at home plate and continues to third base and then to the outfield wall. The interior angle formed between the left and right foul line is always 90 degrees.

Foul Out - An ball that is caught in the air before it touches the ground in foul territory. It is recorded as an out.

Foul Pole - A pole that is located on both foul lines at the outfield wall. It is used by the umpire to determine if hit ball is a home run or a foul ball.

Foul Territory - The area on the baseball field that is not included in fair territory and is not located beyond the outfield wall or in the spectator area.

Foul Tip - A play by the offensive batter where contact is made between the bat and baseball during the swing and the baseball is caught by the defensive catcher.

Full Count - The count on the batter when there is three balls and two strikes.