No, You Can't Catch a Ball With Your Hat

Yankees center fielder Trent Grisham got away with an illegal play when he took off and used his hat to field Brewers batter Isaac Collins' fly ball to deep right-center, a rules infraction that should have resulted in a three-base award had the umpires spotted it.

Replays indicate that in the 9th inning of New York's 4-2 win over Milwaukee, Grisham deliberately took off his uniform cap and used it to help control a fair ball at the wall, which is against the rules, the penalty for which is a three-base award: "Three bases, if a fielder deliberately touches a fair ball with their cap, mask or any part of their uniform detached from its proper place on their person. The ball is in play and the batter may advance to home base at their peril" (Official Baseball Rule 5.06(b)(4)(B)).

The violation went uncalled, resulting in a double with Brewers baserunner R1 Joey Ortiz advancing from first to third base. Had the umpires called and enforced the violation and its penalty, Ortiz would have scored and batter-runner Collins would have been placed at third base.

Video as follows:
Alternate Link: Grisham gets away with uncalled detached hat play deep in outfield