He is also recognized as the host of the first sports talk radio show in history that launched in March 1964 on WNBC (AM).
During World War II, he served the majority of his time in the Armed Forces-Air Force Transport Command in the Pacific theatre.
[9] With years of play-by-play and sports commentary in Buffalo under his belt, Mazer arrived in New York City in 1964 when WNBC (AM) went to its first all-talk format.
Mazer also filled in for segments of the long-running NBC Radio series Monitor, even hosting on occasion.
[10] He served as a color commentator and studio host, working with play-by-play announcer Dan Kelly on CBS' National Hockey League coverage from 1969 to 1970, including the Stanley Cup playoffs.
Most memorably, he covered Game #4 of the 1970 Stanley Cup finals, famously won by the Boston Bruins on Bobby Orr's iconic overtime goal on May 10, 1970.
During the 1960s and 1970s, Mazer did much voice-over commercial work, from L&M Cigarettes, Kodak, Ford automobiles to Trident chewing gum, among many others.
[11] While doing sports for The 10 O'Clock News on WNEW in the late 1970s and '80s, he held a daily contest where a viewer would send in a question to "stump" Bill and would win a prize if he or she did.
[12] He appeared on the cable TV show The Leon Charney Report, as well as minor parts in movies such as Eyewitness, Raging Bull and appearing in episodes of ESPN SportsCentury as an expert on sport figures including Gordie Howe, Lawrence Taylor and Mickey Mantle.