In most cases, the object of a pitch is to deliver the ball to
the catcher without allowing the batter to hit the ball. The ball
is delivered in such a way that the batter either can't hit a pitch
through the strike zone or is compelled to swing at a pitch outside
of the strike zone. If the batter elects not to swing at the pitch,
it is called a strike if the ball passes through the strike zone
and a ball otherwise.
Nearly all action during a game is centered around the pitcher
for the defensive team. A pitcher's particular style and skill
heavily influences the dynamics of the game and will often determine
the victor.
The type and sequence of pitches chosen depends upon the particular
situation in a game. Because pitchers and catchers must coordinate
each pitch, a system of hand signals are used by the catcher to
communicate choices to the pitcher, to which the pitcher either
vetoes or accepts.
Keeping a foot on the pitcher's rubber at the center of the pitcher's
mound, which is 60 feet 6 inches from home plate, the pitcher throws
the baseball to the catcher, who is positioned behind home plate
and catches the ball. Meanwhile, a batter stands in the batter's
box at one side of the plate, and attempts to bat the ball safely
into fair play.
Although the object and mechanics of pitching remain the same
for all pitchers, pitchers may be classified according to their
roles and effectiveness. The starting pitcher begins the game and
he may be followed various relief pitchers, such as the long reliever,
the left-handed specialist, the setup man, and/or the closer.
Famous past Major League Baseball pitchers include Cy Young, Christy
Mathewson, Walter Johnson, Sandy Koufax, Steve Carlton, and Nolan
Ryan. Famous current pitchers (as of 2004) include Roger Clemens,
Randy Johnson, Greg Maddux, Johan Santana, and Pedro Martinez.
Pitching in a Game
Effective pitching is vitally important in baseball. In baseball
statistics, for each game, one pitcher will be credited with
winning the game, and one pitcher will be charged with losing
it. However, pitching is also physically demanding, especially
if the pitcher is throwing with maximum effort. A full game usually
involves 120-170 pitches thrown by each team, and most pitchers
begin to tire before they reach this point. As a result, the
pitcher who starts a game often will not be the one who finishes
it, and he may not be recovered enough to pitch again for a few
days. The act of throwing a baseball at high speed is very unnatural
to the body and somewhat damaging to human muscles, thus pitchers
are very susceptible to injuries, soreness, and general pain.
Teams have devised two strategies to address this problem: rotation
and specialization. To accommodate playing nearly every day, a
team will include a group of pitchers who start games and rotate
between them, allowing each pitcher to rest for a few days between
starts. Also, teams have additional pitchers reserved to replace
that game's starting pitcher if he tires or proves ineffective.
These players are called relief pitchers, relievers, or collectively
the bullpen. The relief pitchers often have even more specialized
roles, and the particular reliever used depends on the situation.
Many teams designate one pitcher as the closer, a relief pitcher
specifically reserved to pitch the final inning or innings of a
game when his team has a narrow lead, in order to preserve the
victory. Generally, relief pitchers pitch fewer innings and throw
fewer pitches than starting pitchers, but may be able to pitch
more frequently without needing multiple days to recover.
A skilled pitcher often throws a variety of different pitches
in order to prevent the batter from hitting the ball well. The
most basic pitch is a fastball, where the pitcher throws the ball
as hard as he can. Some pitchers are able to throw a fastball at
a velocity of over 100 miles per hour (160 km/h). Other common
types of pitches are the curveball, slider, changeup, forkball,
split-fingered fastball, and knuckleball. These generally are intended
to have unusual movement or deceive the batter as to the rotation
or velocity of the ball, making it more difficult to hit. Very
few pitchers throw all of these pitches, but most use a subset
or blend of the basic types. Some pitchers also release pitches
from different arm angles, making it harder for the batter to pick
up the flight of the ball. (See List of baseball pitches.)
After the Ball is Pitched
The pitcher's duty doesn't cease after he pitches the ball. He
has several standard roles at that point. The pitcher must attempt
to field any balls coming up the middle, and in fact a Gold Glove
Award is reserved for the pitcher with the best fielding ability.
He must also cover first base on balls hit to the right side,
since the first baseman might be fielding them. On passed balls
and wild pitches, he covers home-plate when there are runners
on. Also, he generally backs up throws to home plate.