We are used to "magic numbers" - a combination of wins by your team and losses by whoever is behind them - in baseball. The number of teams going to the playoffs is smaller, and the nature of baseball means that each individual game is more subject to luck (which is why they play 162 games), so the mathematical elimination of a team is more significant in that sport. Plus, baseball fans just like math more.
But in other sports this is not so. With more teams in the playoffs, one can make an initial estimate before the season starts how many wins it will take to go to the playoffs, and modify that only slightly as it progresses. In football, if you win 11 games you are going to the playoffs, if you only win 8 you're not. There are occasional outliers - the Patriots a few years ago, Seattle this year - but is so unusual as to be in itself a subject of comment. People don't talk about magic numbers, because by the time they come into play in the last two games, the situations can be described in terms of actual matchups, not just generic games won or lost.
Basketball (hockey too, but I care less about that) is somewhere between. Technically, there are three teams - San Antonio, Miami, and Boston which have Magic Numbers of 10 or so. That is, any combination of 10 of their wins added to losses of the 9th-place team and they make the playoffs. But the reality is simpler. Those teams could lose all the rest of their games, literally all, and still make the playoffs. Even Chicago is right on the border for that. The 9th-11th place teams would have to win at such a surprising rate as to make that unlikely. Even though their magic numbers are over 10, they have already qualified for the playoffs by number of victories.
Chicago, BTW. They got defensive genius Tom Thibodeau as coach this year. They have scored only one more point per game, but they have held opponents to almost seven less than last year. They have gradually passed Atlanta and Orlando in the East, and could reasonably catch either the Celtics or the Heat before season's end. And in the playoffs, I rate them the equal of the two teams ahead of them - much as it pains me to say that. No one seems to be mentioning this angle up here in New England - maybe because they got Thibodeau from the Celtics. Shouldn't it be the main story about Chicago, which may be the best defensive team in the league now?