While not a power hitter, he hit for average and was a good contact hitter for most of his career. His success was short-lived, however, as he broke his arm in 1930, and a torn ligament in his leg prematurely ended his playing career. Fonseca is perhaps best known as one of the first men to use film in analyzing baseball games and finding flaws in players.
lieutenant is said that his interest with cameras began while shooting Slide, Kelly, Slide in 1927.
As manager of the Chicago White Sox, he used film extensively. After retiring from playing the game, he was director of promotions for both leagues.
Fonseca worked on World Series highlight films from their inception in 1943 through 1969, as an editor and director, and narrated the World Series films from 1949-"53 and 1955-"58 (Jack Brickhouse narrated the 1954 World Series film) Television sportscaster Bob Costas wrote of Fonseca"s narration: " vocal stylings were somewhat less than mellifluous, but still endlessly entertaining." Fonseca was batting coach for the Chicago Cubs for many years, until quite late in life. Fonseca died in Ely, Iowa at age 90, one month after the Loma Prieta earthquake hit near his birthplace of Oakland, California.