Q: Why is December 1 the cutoff date for separating release years?
A: People, perhaps irrationally, expect End-of-Year lists to come out before the end of the year, or at least that's what everyone else does. In early Polls, the cutoff date was Thanksgiving, but we switched to December 1 because it's easier to remember when you're comparing a release date. Nonetheless, the ballot invites go out earlier, in mid-November. And while many critics get advances before release date, many more don't, plus there are many records that don't get promoted (let alone known through word of mouth) until even later. The only silver lining here is that the number of records released in December drops off considerably.
Q: Is the December 1 cutoff date strictly enforced?
A: No. It isn't always easy to determine the release date (or even year). Also, many records have multiple release dates, depending on format, some overlapping years. Many records don't get noticed for some time after their release. On the other hand, on rare occasions an early-December release may be widely promoted ahead of time. (And every year someone votes for a promo where the release date is in the next year. That elicits a frown, but doesn't get stricken off.) We do recommend that you follow the date cutoff guidelines, but will accept exceptions. We do warn, however, that voting for records outside their year slot is often a waste of a vote, except in the rare case of crossover votes.
Q: What are carryover votes?
If a record gets votes in one year and more votes and more points in the next year, the previous year's votes and points are added to the following year's totals. This rarely happens, and rarely makes any appreciable difference. This rule follows a similar one in the Pazz & Jop poll, most notably when Michael Jackson's Thriller won the poll the year after it came out.
Q: If everything on a record is previously unreleased, shouldn't it be a New Release?
A: Only if all of the material was recorded in the last ten years. Any albuns containing older material should be considered as Historical (Rara Avis). This is a common source of confusion, albeit less so than under the pre-2012 rule. Most jazz albums provide recording dates, especially if they were recorded more than a few years ago. It is much harder to determine previous release history. It also seems a bit unfair to current musicians to have to compete against a previously unreleased set by Thelonious Monk or John Coltrane.
This rule was changed in 2012. Before that, the we drew the line strictly on whether all the material was previously unreleased or any was reissued. This allowed Charles Mingus to finish 2nd in 2007, and Sonny Rollins to win in 2008 and 2011 with his Road Shows archives. (The Monk/Coltrane At Carnegie Hall was released in 2005, so was fresh in mind.) Most other jazz polls made a distinction between New and Historical releases (with Rollins in the latter category).