Sentence:  It is the year when ( 1 ) amiable Jim Gentile of the Baltimore Orioles ambled to the plate in consecutive innings with the bases loaded and , in unprecedented style , delivered consecutive grand-slam home runs ; ( 2 ) Willie Mays of the San Francisco Giants borrowed a teammate 's bat and <WSD>became</WSD> the ninth big leaguer to stroke four home runs in a game ; ( 3 ) the Milwaukee Braves tied a major-league record with fourteen home runs in three games and lost two of them ; and ( 4 ) catcher Johnny Blanchard of the New York Yankees matched a record with home runs in four successive times at bat , two of them as a pinch-hitter . 
Meaning of the word marked with <WSD> tags:  undergo a change or development