Over their last five games, the Celtics  have held the Heat, Spurs, Bulls, Pacers and 76ers — all likely playoff-bound teams — to just 80.6 points per game. That ridiculous stretch included the lowest scoring output of the Miami Thrice era and Indiana’s worst offensive game this season (both 72 points).
The point? A case can be made, rather easily, that the C’s now own the NBA’s best defense.
This recent run vaulted the Celtics to No. 1 in points allowed per 100 possessions (95.3). Their 89.3 points allowed per game still ranks third behind the only other teams that give up fewer than 90 points a night — the Sixers (88.5) and Bulls (88.9) — but that’s dropped to an NBA best 83.4 points surrendered over the past 10 games.
In fact, as colleague Paul Flannery noted, the Celtics have allowed 80 points or fewer in six of their last 12 games (including four of their last six), holding opponents to 40 percent shooting or worse in eight of those 12 contests.
For the season, the Celtics have held opponents to the league’s lowest field goal percentage (41.8%) and 3-point percentage (29.8%), both still tops in the NBA and even better over the past 10 games (38.7 FG%, 25.2 3P%). They make an offense’s life miserable everywhere on the court, ranking top-10 everywhere from at the rim (3rd) to 3-9 feet (8th) to 10-15 feet (1st) to 16-23 feet (7th) to 3-point range (1st).
Aditionally, the C’s hold teams to the league’s lowest assist rate, meaning only 17.5 percent of opposing possessions result in assists. That’s a lot of one-on-one basketball, and that’s a good thing for the Celtics defense. Doc Rivers  despises when his team plays “hero ball,” so he must love seeing other teams play it against his.
Per 100 possessions, the C’s 15.6 blocks (5th) and 14.7 percent turnover rate (5th) aren’t shabby, either.
All five of the current Celtics starters rank among the top 62 overall defenders in the league this season in terms of points allowed per possession, according to Synergy Sports Technology .
Player: points allowed per possession (rank)
Improvement in the Celtics defense since the All-Star break is no fluke. Rivers made two significant changes to the lineup: 1) moving his best and most vocal team defender (Garnett) to center; and 2) inserting both a great one-on-one defender (Bradley) and a very good post defender (Bass) into the starting lineup.
Those adjustments allowed Bradley and a reinvigorated Rondo to cement a group of guards that has allowed an NBA best 31.1 points per contest to opposing backcourts over the last 10 games. Bradley and an engaged Rondo require less help defensively, allowing Garnett and Bass to hold down the fort rather than cheating from the post.
As a result, the Celtics starting lineup owns a ridiculous efficiency differential (+20.1) that’s 32.2 percent better than the league’s next-best team since the All-Star break and even more absurdly good (+30.6) — or 37.8 percent better than the second-ranked Thunder starters — over the last 10 games.
Sprinkle in some shot-blocking and rebounding from reigning D-League Defensive Player of the Year Greg Stiemsma , whose adjustment to the team’s defensive schemes has improved tremendously, and the Celtics now own the best defense in the NBA — one that may only improve should Mickael Pietrus  return.
(Have a question, concern or conception for tomorrow’s Irish Coffee? Send a message to @brohrbach  on Twitter.)