Announcers bridge the gap between players and spectators. They tell us which skaters are jamming, which team just called a time out, what the score is, and who's in the penalty box. They also explain the game for derby virgins, give the sponsors some airtime, and amuse us with their antics during lulls in the action.
In researching this post, Flocci discovered that there's an Association of Flat Track Derby Announcers, and her top three announcers1 are all members. AFTDA's mission statement and code of conduct cover the basics of good announcing (don't show up drunk, know the rules, don't interfere with the refs, etc.), but there are a few other things that separate the good from the bad.
First off, know your terminology. We went to a bout recently where one of the announcers used "power play" to mean "power jam," and Flocci just about twitched herself into a seizure. An announcer should also know the skaters' names and numbers (not just from the bout program) and be able to identify them fairly quickly. We've seen announcers talk to every skater before a bout to make sure they get the names and numbers right, and to learn taglines that might not have made it into the pre-bout paperwork. This makes it much easier to call the game, which, in turn, means the audience gets a smoother play-by-play.
Learning how to make do with a sub-par sound system is another mark of the good announcer. If you find during your sound check that the only way the audience can hear you is if you hold the mic a foot away from your face and stand precisely seventeen feet from the amp, then that's what you need to do. If we can't hear you, there's no point in you being there at all.
Lastly, have some class. You can be silly and weird, but be professional, too. We want to laugh with you, not at you. (When Rock Thudson wore that fringed belly shirt, it was a little of both.)
1 Rock Thudson, Candy Corn-ary, and Pelvis Costello, in case y'all were wondering.