Baseball Positions by Number: What Each of the Nine Does

Baseball numbers its nine fielders, and scorers use those numbers as shorthand: 1 pitcher, 2 catcher, 3 first baseman, 4 second baseman, 5 third baseman, 6 shortstop, 7 left fielder, 8 center fielder, 9 right fielder. That is the numbering in MLB's scorekeeping glossary, and it is why "6-3" means a ground ball to the shortstop, thrown to first for the out.

The order runs pitcher and catcher first, then the bases from first to third, then the shortstop, then the outfield from left to right. The shortstop is the one number out of geographic sequence, which is worth memorising early.

The nine numbers at a glance

The pitching distance comes from MLB's field dimensions entry, which also fixes the infield as a 90-foot square.

A typical alignment, and what the rules actually fix

Here is the conventional picture, seen from behind home plate:

                 8
       7                   9
             6       4
       5         1         3
                 2

Only two of those dots are fixed by the rules. Rule 5.02 of the 2026 Official Baseball Rules says the catcher "shall station himself directly back of the plate," and the pitcher must take a legal pitching position to deliver the ball. Every other fielder may stand "anywhere in fair territory" — subject, since 2023, to the infielder positioning limits.

Those limits are in Rule 5.02(c). When the pitch is released, four players besides the pitcher and catcher must have both feet in front of the outer edge of the infield dirt, with two of them entirely on each side of second base, and the two on each side may not swap sides during the inning except around a substitution. The rule's own comment gives the purpose: preventing more than two infielders on either side of second base. MLB's glossary entry on defensive shift limits adds that four-outfielder alignments are out too, and that the penalty was adjusted going into 2025, so the batting team can now be awarded a base when the violating fielder is the first to touch the ball.

In practice the rule keeps the infield close to the diagram above: two infielders on each side of second base, usually the shortstop and third baseman on the left and the second and first basemen on the right.

What each position does

The battery: 1 and 2

The rulebook's definition of a pitcher is simply "the fielder designated to deliver the pitch to the batter." Once the ball is hit, he becomes a fielder like any other; the infield fly rule even counts the pitcher and catcher as infielders. The different jobs pitchers do over a season — starting, relieving, closing — are a separate subject, covered in baseball pitching roles explained.

The catcher is involved in every pitch, and the scoring rules show it. Rule 9.09(b) gives the catcher an automatic putout when a batter is called out on strikes, so a catcher's putout column climbs with almost every strikeout his pitchers record — the exceptions come on uncaught third strikes when the batter is allowed to run. He is also one of only three fielders with an equipment rule of his own: Rule 3.04 caps the catcher's mitt at 38 inches in circumference and fifteen and a half inches from top to bottom. (The pitcher's glove has its own rule, 3.07, which is about colour rather than size.)

The infield: 3, 4, 5 and 6

First base (3) is where the most common force out is made. MLB's force play entry points out that first base tends to have the most force plays, because a batter can be forced out there whenever he hits a fair ball that is not caught in the air. The first baseman gets a glove rule too: Rule 3.05 allows a mitt up to 13 inches long and 8 inches wide across the palm.

Second base (4) and shortstop (6) form the middle infield, one on each side of the bag. A ground ball to one of them often ends with a throw to the other at second, which is exactly what the notation 6-4-3 and 4-6-3 records.

Third base (5) is the far corner of the infield; a throw from there to first crosses the whole diamond.

FanGraphs adds one observation about who ends up where: left-handed players do not play shortstop, so the best left-handed defenders land at other positions.

The outfield: 7, 8 and 9

The rules define the outfield as the part of the field "most distant from home base." Outfielders catch fly balls, field hits that get through, and throw to the bases to stop runners advancing. The center fielder covers the middle, and FanGraphs' positional adjustment rates the position as harder than either corner (more on that below).

An outfielder can also be pulled in. The shift limits still allow a team to station an outfielder in the infield or in shallow grass in some situations, and the infield fly definition treats any outfielder who stands in the infield on the play as an infielder for that rule.

The designated hitter has no number

The designated hitter bats in place of the pitcher and "does not take the field on defense," in MLB's glossary wording. He therefore never appears in fielding notation; lineups and scorecards label him DH.