Among my early, fond memories of Mad Magazine was a Nasty File when they identified the National Basketball Association as the only league playing an 84-game season to determine which two teams don't qualify for the playoffs. Even then though I knew it wasn't quite true, as the National Hockey League let every team, including several in the American Basketball Association, into their playoffs. Also they had the divisions use odd names like ``Patrick'', which I actually liked because it avoided making obvious anomalies like how the Atlanta Braves used to be in the National League West. Names that don't mean anything are useful and flexible in that way.
I learned today that although the National Hockey League experimented with a staggering number of variations for its playoffs from 1917-18 through 1942-43 when the league settled down to the ``Original Six'', it turns out there've been only three years when fewer than half the teams in the league actually played in the playoffs. (Four, I suppose, if you count the locked-out season.) More, in two of those --- 1919-20 and 1924-25 --- the schedule format was designed for at least half to get in. In 1919-20 Ottawa won both halves of the split-season schedule for an automatic berth, reducing the number of playing teams by one; in 1924-25 first-place Hamilton refused to participate in the playoffs. In 1925-26 only three of the seven teams were in the playoffs, the only time less than half the league was scheduled to get in.
Most striking was the 1917-18 season: the season started with four teams (the Montreal Canadiens, the Toronto ... uh ... Torontos, the Ottawa Senators, and the Montreal Wanderers), with the plan being for two teams, winners of each half-season, to be in the playoffs. But partway through the first half of the season the Wanderers' arena burned down and the team folded (and, apparently, borrowing the Canadiens' place would just be crazy talk), so they finished with three teams in the league and two of them in the playoffs. You have to feel sorry for the Senators. Also, the first half of the season was fourteen games, while the second half was somehow eight games. I feel bad for their having to go through all the trouble of playoffs for that small a league.
Trivia: Fort Wayne (Indiana)'s baseball club in the National Association of 1871 played 19 championship contests (that is, games which counted in the standings) before folding; no team in the league played more than 33 that season. Source: The Rules of Baseball: An Anecdotal Look at the Rules of Baseball and How They Came To Be, David Nemec.
Currently Reading: The Civil War In The American West, Alvin M Josephy, Jr.