Nets' center rotation, 76ers' bench and the most important lineups for Eastern Conference's top contenders

These are the fivesomes that could determine the Eastern Conference champion

One of the NBA regular season's dirtiest secrets is how little teams care about lineup decisions, at least as they relate to winning basketball games. Case in point: Both of last season's Finals teams -- the Los Angeles Lakers and Miami Heat -- removed a regular-season starter from their rotation entirely. JaVale McGee hardly played for the Lakers beyond the first round. Meyers Leonard only reappeared for Miami once Bam Adebayo got hurt. The regular season is about survival, and survival rewards caution over optimization.  But winning in the playoffs means scraping the bottom of the barrel for every conceivable advantage, and losing in the playoffs often comes down to a single disadvantage. The 2019 Philadelphia 76ers beat the stuffing out of the eventual champion Toronto Raptors when Joel Embiid was on the floor, for instance, but lost the 99 minutes he sat in that series by a preposterous 109 points. The 2017 Cleveland Cavaliers lost their title shot in similar fashion against the Golden State Warriors. They essentially played the greatest team of all time to a draw when LeBron James was on the floor, but when he went to the bench? They got clobbered by 27 points in 28 minutes.  As extreme as lineups losing by a point per minute might seem, the concept isn't particularly rare. Plenty of playoff losses can be traced back to a single defective unit, and virtually all championships are won behind the strength of a team's best fivesome. So as the playoffs approach, let's take a look at the five-man units that will make or break each contender's championship hopes. First up, the Eastern Conference's top four seeds.