Fractions

Fractions may signify either exact figures or inexact estimations: He pitched 4 2/3 innings; She played 9 1/2 seasons in Minnesota.

Express figures greater than 1 in X X/X format (see examples above); spell out figures less than 1: four-sevenths; two-thirds; one-fourth

Use a hyphen and spell out “half” when preceding a noun: a half-yard; a half-second

Decimals

Decimals only signify exact numbers or amounts: She crossed the finish line in 9.32 seconds; He posted a 3.84 ERA.

Two decimal places is generally the preferred expression, unless the statistic or data point typically is presented in a different format: 4.3 bWar; 89.4 passer rating

Note regarding baseball and softball: Never use decimals to express thirds of an inning, e.g. “3.2 innings,” in copy. Always use fractions: 5 2/3 innings; one-third of an inning