With their 96-83 win over the Cleveland Cavaliers on Wednesday night, the Boston Celtics just got that much closer to becoming the first Eastern Conference team to eliminate a LeBron James-led squad in eight years. (Incidentally, the last team to do it also wore Celtics green.) And once again, it was all about the Celtics’ home-court advantage playing at TD Garden, where Boston is a perfect 10-0 in these playoffs.
Where does this rank among the playoffs’ greatest historical performances at home? If we use FiveThirtyEight’s Elo ratings to measure each team’s schedule-adjusted performance in every game, the Celtics are winning by 7.2 more points per game than we’d expect based on the quality of their opponents. Since the 1984 playoffs (when the NBA expanded the field to its modern 16-team format), that ranks these Celtics as the 10th-best home team in any single postseason:
|Rk||Season||Team||Wins||Losses||PPG Diff.||Vs. Expected|
|4||2018||Golden State Warriors||7||1||+14.8||+10.5|
|6||2016||Oklahoma City Thunder||6||3||+13.3||+8.0|
|8||1984||Los Angeles Lakers||9||2||+14.5||+7.6|
It wasn’t always pretty in Game 5. Despite rookie swingman Jayson Tatum’s big numbers (24 points, 7 rebounds, 4 steals and 2 blocks), the Celtics’ 36.5 percent field-goal percentage was the 10th worst by a winning team in a conference final game since 1984. But Boston’s defense made up for it. It held the Cavaliers to 88.0 points per 100 possessions, their third-worst offensive game of the whole playoffs, rendered three Cavs starters (JR Smith, Tristan Thompson and George Hill) practically invisible and limited a visibly exhausted LeBron to only the fourth game of the postseason in which he didn’t personally account for at least 20 percent of the positive actions by either team while on the court.
(That’s according to NBA Advanced Stats’ Player Impact Estimate metric, in which LeBron “only” graded out at 18.1 percent in Game 5. He still led all Cavs who logged any meaningful playing time, but James’s PIE was below his playoff average of 23.1 percent. That’s how high a standard we hold LeBron to: Somehow it’s seen as disappointing if he doesn’t literally do the work of two players when he’s in the game.)
The Celtics’ home-court advantage in these playoffs has generally been fueled by offense as much as defense — even after Game 5, they’re scoring 11.5 more points per 100 possessions at home than on the road, while allowing 10.8 points per 100 possessions fewer — but on Wednesday night, it mostly came down to the work Boston put in at the defensive end. Pesky Celtics defenders Marcus Morris and Marcus Smart led the way on this end, holding Cleveland shooters to the game’s two lowest shot-quality numbers as individual defenders, according to Second Spectrum’s quantified shot quality metric.
As for the Cavs, Game 5 continued their yearlong pattern of extreme up-and-down basketball. After losing Games 1 and 2 by an average of 19.0 points per game and then winning Games 3 and 4 by an average of 19.5, they turned around and lost Game 5 by 13. Predictably, it happened as they reverted back to their poor-shooting ways; they made just 26.5 percent of their 3-pointers Wednesday, which is the kiss of death for this Cleveland team.
But who can say when they’ll heat up again? As The Ringer’s John Gonzalez wrote earlier this week, we all need to stop waiting to find out who these Cavs really are. There’s nothing to really learn about them at this point, except that they’re maddening and impossible to predict. And with Cleveland in a do-or-die situation at home in Friday’s Game 6 — remember, James’s teams are 10-3 when facing elimination since 2012 — the roller-coaster ride is far from over.