fielder has control of ball in glove

RulesMLB Umpire Manual

LEGAL CATCH

Definitions of Terms: The Umpire should find that a legal catch has occurred pursuant to Definitions of Terms, “Catch,” or valid force out or tag has occurred pursuant to Definitions of Terms, “Tag,” if the fielder had complete control over the ball in his glove, and drops the ball after intentionally opening his glove to…