PITTSBURGH — Mark O’Mahoney was like a kid again, crouched on the floor with an aggie cocked in his thumb and aiming at one of 13 target marbles arranged in an “X” at the center of a 10-foot circle.

WILDWOOD, N.J. – Two teenagers from Maryland have taken all the marbles. Marilyn Fisher and Dominic Rudakevych of Middletown Valley won the 91st annual National Marbles Championship in Wildwood, New ...