Fly-ball priority

• Center fielder over the other outfielders.
• Any outfielder over any infielder.
• Shortstop over the other infielders; second baseman over first baseman.
• Infielders over the pitcher and catcher. The pitcher takes a pop-up only when nobody else can.

The exceptions that settle close calls

• Standing up beats diving. A ball an infielder catches standing up and an outfielder would have to dive for is the infielder's.
• Camped beats running. On a very high ball, an infielder already under it keeps it over an outfielder still running.
• The infield belongs to the infielders. A ball coming down on the dirt is an infielder's; the catcher takes anything straight up around home.

Everyone who can reach the ball runs for it as if it's his. Priority decides who keeps going and who peels off.