Even though there has been an electronic scoreboard above the bleacher seats in center field at Fenway Park for many years (since replaced in 2011 by a high-definition screen), fans often refer to the manual scoreboard at the base of the Green Monster to keep track of the action on the field and at other parks around the league. This feature was installed in 1934 and it is one of the few remaining manually-operated scoreboards in baseball.
During every home game, there are three operators inside the left field wall that work to keep the scoreboard as up-to-date as possible. Green and red lights signal the number of balls, strikes, and outs, 16-inch-square numbers are used to indicate runs and hits, and 12-by-16 inch square numbers are used to show errors, innings, and the number of the current pitcher.
In the mid-1970s, the wall was remodeled and the scoreboard was changed to only show out-of-town American League scores; however, in 2003, the National League scores were added back to the scoreboard, though these scores may only be updated between innings. Another update in 2005 added a reference to the current standings in the American League East. Also, if you look closely, you will find the initials of former owners Thomas A. Yawkey and his wife Jean R. Yawkey written in Morse code.