Sports radio (or sports talk radio) is a radio format devoted entirely to discussion and broadcasting of sporting events. A widespread programming genre that has a lower audience appeal than formats which attract wider audiences, sports radio is characterized by an often-boisterous on-air style and extensive debate and analysis by both hosts and callers. Commiserate with the format to attract listeners, many sports talk stations also carry play-by-play of local sports teams as part of their regular programming. Hosted by Bill Mazer, the first sports talk radio show in history launched in March 1964 on New York’s WNBC (AM). Enterprise Radio became the first national all-sports network, operating out of Avon, Connecticut, from New Year’s Day 1981 through late September of that year before going out of business. ER had two channels, one for talk and a second for updates and play-by-play. ER’s talk lineup included current New York Yankees voice John Sterling, New York Mets radio host Ed Coleman and former big-league pitcher Bill Denehy. Sports talk is available in local, network and syndicated forms, is available in multiple languages, and is carried in multiple forms on both major North American satellite radio networks. In the United States, most sports talk formatted radio stations air syndicated programming from ESPN Radio, Yahoo! Sports Radio, Sports Byline USA, Fox Sports Radio, CBS Sports Radio, or NBC Sports Radio, while in the Spanish language, ESPN Deportes Radio is the largest current network. In contrast, Canadian sports talk stations may carry a national brand (such as TSN Radio or Sportsnet Radio) but carry mostly local programming, with American-based shows filling in gaps. Compared to other formats, sports radio is not as popular on Internet radio; as a live and interactive format, it does not lend itself well to voice-tracking (thus raising the cost and required labor to keep a station running 24/7), and most sports leagues place their radio broadcasts behind a paywall or provide their broadcasts directly to the consumer, though sports podcasting is a popular alternative to address this problem. As with most other radio formats, sports radio uses dayparting. ESPN Radio, for instance, insists that its affiliates carry Mike and Mike in the Morning during morning drive time to provide as much national clearance as possible; in contrast, it carries less prominent programming in the afternoon drive to accommodate local sports talk, as well as in the evening (for its first two decades, rolling score updates aired under the banner of GameNight) to allow stations to break away for local sporting events. Somewhat unusually for radio, the late-night and overnight hosts have more prominence on a sports talk network, due to a near-complete lack of local preemption; Sports Byline USA, for instance, only operates overnights. Sports radio stations typically depend on drawing an audience that fits advertiser-friendly key demographics, particularly young men with the disposable income to invest in sports fandom, since the format does not have the broad appeal to reach a critical mass in the general public. Prominent sports radio stations typically get their greatest listenership from live play-by-play of local major professional sports league or college sports franchises; less prominent stations (especially on the AM dial) may not have this option because of poorer (or for daytime-only stations, non-existent) nighttime signals and smaller budgets for rights fees.