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No Eastern Conference lineup has played more than 714 total minutes this season. That group—Atlanta's starting lineup—represents just 19.4% of the total minutes played by the Hawks this season. Put simply: lineup continuity is a very rare thing in the regular season. Even the highest-usage groups represent only small fractions of a team's total minutes in the regular season, where injuries and experimentation lead to an almost constant state of flux.

The playoffs are a different beast. Teams run their best players into the ground. They find matchup holes and exploit them until the other team finds a solution. Rotations shorten and coaching grows significantly more important. When the postseason arrives, every minute devoted to every combination of players can be the difference between winning and losing.

So with the playoffs swiftly approaching, let's go team-by-team and look at the lineups that will make or break their postseason runs. We'll kick things off in the Eastern Conference. Here are the five most important units of the 2023 Eastern Conference playoffs (listed in order of the current standings).

*all lineup stats via Cleaning the Glass

1. Milwaukee Bucks

The lineup: Jrue Holiday, Pat Connaughton, Khris Middleton, Jae Crowder, Giannis Antetokounmpo

Total possessions this season: 0

Net rating this season: N/A

With apologies to possible Defensive Player of the Year Brook Lopez, Giannis at center is the NBA's preeminent lineup cheat code. The Bucks are outscoring opponents by 11.9 points per 100 possessions in that alignment this season, and that figure has been as high as 17.7 back in 2020. 

It gets even more lethal in the postseason, where Lopez's (few) defensive flaws became easier to pick at. In the 2021 Finals, Chris Paul and Devin Booker used the drop-coverage Lopez has to play defensively to create a nearly endless stream of floaters and mid-range jumpers, and when the Bucks sent help on those looks, the Suns just turned around and shot 20-of-40 from 3-point range in Game 2. Mike Budenholzer turned the series around in part by playing smaller. Bobby Portis, benched in the second round against Brooklyn, defended at the level of the screen. P.J. Tucker-led lineups switched more than any Budenholzer unit ever has.

The Bucks won the championship. That's the value of defensive versatility in the postseason. Lopez might be the NBA's best pure rim-protector, but he's a somewhat limited one given his immobility. Antetokounmpo is a flawless defender, and sticking him at center allows Budenholzer to tailor his scheme to the matchup while supercharging his offense in the process. What the Bucks lose in Lopez's post game, they more than make up in additional speed and ball-handling when they go small.

This option wasn't really available to last year's Bucks. Khris Middleton's injury was the story of their second-round loss to the Celtics, but nearly as important was Tucker's absence. The Bucks simply lacked the defensive personnel to go small. They started Portis at small forward. Their most-used Giannis-at-center lineup featured Pat Connaughton at power forward. By Game 7, Budenholzer had run out of strategic wrinkles to throw at Boston. The Bucks just collectively decided to allow Grant Williams to shoot and hoped he'd miss. He attempted 18 3-pointers in that game, the second-most ever in a single playoff game.

Milwaukee traded for Crowder in part to replace what Tucker gave them in 2021. Holiday and Middleton are lineup givens, capable of switching onto anyone in the Eastern Conference not named Joel Embiid (that's what Lopez is around for). The only question here is who Budenholzer chooses as the fifth Buck for these lineups. Wes Matthews is the defensive choice. Grayson Allen is the offensive choice. Both will get situational looks, but the middle ground choices are Jevon Carter (shooting a career-best 42.3% from deep!) and Connaughton. In all likelihood, Connaughton's experience and height probably gives him the edge.

But whomever Budenholzer chooses is going to be a part of the single most dangerous unit in the playoffs. Nobody has truly solved the "Giannis at center" problem yet, and with Crowder replacing Tucker, it doesn't seem especially likely that someone does this spring. 

2. Boston Celtics

The lineup: Derrick White, Jaylen Brown, Jayson Tatum, Al Horford, Robert Williams

Total possessions this season: 143

Net rating this season: +45.1

Considering what we just covered with the Bucks, it'd be tempting to just find the best lineup featuring Grant Williams, who earned a reputation last postseason as the "Giannis stopper." In truth, Al Horford was actually far more effective against him statistically a season ago. Antetokounmpo shot 27-of-58 with Williams as his primary defender last postseason, but only 33-of-91 against Horford, though it's worth noting that these numbers are somewhat skewed by the number of double-teams and walls Antetokounmpo faced with Middleton out last season. Williams has had such an uneven season that it's going to be hard to justify major minutes for him even in a good matchup.

The core trio any Celtics lineup needs to be built around is Tatum, Brown and White, who has somewhat definitively been Boston's third-best player this season. Lineups featuring the three of them have outscored opponents by 11.4 points per 100 possessions, and with Marcus Smart dealing with a lingering ankle injury, White has been by far Boston's best guard defender this season. Smart may be one of the team's leaders, but in truth, he's probably Boston's third-best guard right now, and despite playing more minutes with the four other players listed above than White, Boston has lost those minutes by 16.1 points per 100 possessons. The major question Joe Mazzulla is going to have to answer is whether he wants to go small with Malcolm Brogdon for the sake of stabilizing the offense, or if he wants to go big with Horford and Williams for the sake of his defense.

Mazzulla has largely prioritized offense this season. Ime Udoka prioritized defense last season. The double-big lineup, assuming Williams is healthy, is probably going to be a necessity this postseason even if Mazzulla has leaned small. The incentive is obvious against Philadelphia. Keeping two bigs on the floor makes it harder for Joel Embiid to get either one of them into foul trouble because neither has to defend him on every possession.

The Bucks are a tougher nut to crack. Budenholzer will stick with Lopez for the most part against bigger lineups. In the past, that would have meant a parade of open 3-pointers, especially for a Boston offense that takes the second-most in the NBA. But Milwaukee has done a good job this season at least sneaking back to around average in terms of opponent 3-point attempts (and, more importantly, opponent corner 3-point attempts) with some slight schematic tweaks. The Celtics hardly ever get to the rim, and would do so even less against Lopez lineups.

But the Celtics should feel good about their chances in a defensive slugfest. Tatum and Brown are better equipped to win those sort of tough shot-making games than Antetokounmpo and Middleton, and Smart is sitting in their back pocket if the Bucks find ways to pick on the smaller White. There's no great solution for the Bucks, but this is probably Boston's likeliest path to victory.

3. Philadelphia 76ers

The lineup: Tyrese Maxey, De'Anthony Melton, Jalen McDaniels, Georges Niang, Paul Reed

Total possessions this season: 18

Net rating this season: +56.7

No player in recent NBA history has been victimized more by his own backups than Joel Embiid. He has played in nine playoff series in his career and lost five of them. However, if you only counted the minutes he spent on the floor, the 76ers would be 7-2 in series featuring Embiid. One of those losses came in the 2020 bubble with an injured Ben Simmons, and the other came last season, when James Harden inexplicably melted down against the Miami Heat. Philadelphia typically wins the Embiid minutes pretty handily.

It's the rest of the game that gives them so much trouble. In 2019, they managed to outscore the Raptors by 90 points in the 237 minutes Embiid played... only to get outscored themselves by 109 points in the 99 minutes that he sat. The Raptors literally outscored the 76ers by more than one point per minute when Embiid rested. This has been a problem for his entire career, and it's one that Doc Rivers has exacerbated with two maddening tendencies:

  • Rivers loves bench mobs. He has devoted 232 minutes this season to the five-man group of Montrezl Harrell, Georges Niang, Shake Milton, Matisse Thybulle and Tyrese Maxey. That is the only five-man lineup in basketball this season to play at least 200 minutes with at least four reserves, and for much of the season, Maxey was coming off the bench himself. This isn't just a regular-season trend either. In their 2021 loss to Atlanta, Rivers' third-most used lineup featured neither Embiid nor Ben Simmons. Staggering is modern coaching 101, and Rivers still hasn't fully embraced it. Most of Philadelphia's lineups since the All-Star break have featured either Harden or Embiid, but Rivers' history is so full of bench mobs that we can't pretend that a sustained stagger is inevitable.
  • Rivers hates small-ball. The 76ers had a plus-14.5 net rating with Tobias Harris or Georges Niang at center last postseason with Embiid hurt, but Rivers gave them only 31 possessions in that alignment. Not only did DeAndre Jordan get killed in twice as many possessions at center, but he openly mocked the media for questioning the decision. "We like DJ," Rivers said at the time. "We're gonna keep starting him whether you like it or not."

This therefore means that many of the more obvious solutions for Philly's backup center problem, like going small with P.J. Tucker or extensive staggering, may not be Rivers' first instinct. But there's a glimmer of hope in the form of backup big man Paul Reed. After years of hope from Philly fans clinging to his performance as the 2021 G-League MVP, "B-ball" Paul is finally starting to emerge as a legitimate backup center. Philadelphia has won his 209 minutes in March by 59 points.

Eventually, Rivers is probably going to settle on Harden and Reed as bench partners, but thus far this season, he's devoted nearly twice as many possessions to the Reed-Maxey pairing. The lineup we landed on above is the second-most used Reed lineup since March 1 (excluding a Harden pairing that we may also see). The lone difference is that Melton replaces Milton in this iteration, as Philadelphia will likely trim its guard rotation to Maxey, Melton and Harden. The exact combination of players is subject to change. But given his history, Doc Rivers is almost certainly going to try a lineup or two in the postseason built around Reed and the reserves.

If that lineup has a short leash and fails, there are alternatives. Their starting lineup with Melton in place of Embiid and Tucker moved to center has outscored opponents by 11.6 points per 100 possessions in 184 possessions. That is a lineup we're likelier to see against Boston than the enormous Bucks. There will be other Tucker-at-center alignments, likely with Maxey replaced by a wing, but the takeaway here is that Philly's playoff hopes are going to rely on its ability to survive the minutes without Embiid. Reed is going to be their first possible solution, and if he can stick, the 76ers will prove to be a very tough out.

4. Cleveland Cavaliers

The lineup: Darius Garland, Donovan Mitchell, Isaac Okoro, Evan MobleyJarrett Allen

Total possessions this season: 800

Net rating this season: +7.8

Cleveland has tried seven different players alongside its core four this season, and basically all of them have been moderately successful. For now, we can probably rule out Ricky Rubio (as a fit issue), Danny Green (out of the rotation) and Dean Wade (ditto) as the fifth banana come playoff time. Cedi Osman has gotten a bit more of a look lately, but largely in bench lineups. Lamar Stevens has been given a real opportunity to prove he belongs with the starters, but his high-energy skill set probably serves Cleveland best off of the bench.

That really only leaves two players for the final slot. Caris LeVert lineups have been the most successful among groups involving the other four starters. The Cavs are blasting opponents by almost 14 points per 100 possessions in those minutes, and perhaps more importantly, LeVert has been the player J.B. Bickerstaff has trusted most to support his stars in the clutch. He's played 128.9 minutes in the clutch this season. Isaac Okoro has played only 50.6, and while he's played more than double the possessions with the starters as LeVert, the Cavs have won those minutes by only 7.8 points per 100 possessions.

All of this points to LeVert, not Okoro, as the fifth Cavalier come playoff time, but his skill set lends itself much more to the regular season. Spare ball-handling is welcome in the 82-game grind. Mitchell and Garland are setting everything up when it counts. LeVert is making 38% of his 3's this season, but he was a 33.3% career marksmen in the six years prior. Defenses are going to let him shoot, and even if he makes those looks, he's going to have a hard time surviving defensively. He's having perhaps the best year of his career on that end of the floor, but the defensive demands of playing next to two small guards are simply too great for him.

This is where Okoro comes in, especially against Boston. Evan Mobley can defend any big wing Cleveland runs into, but someone has to be able to chase opposing star guards. That's going to be Okoro. He'll get the first crack at Jaylen Brown, Jrue Holiday and James Harden in the Eastern Conference playoffs, and while he's no stopper, he has the physical tools to at least make their lives difficult.

Offensively, he's going to have to answer the same question as LeVert: can he make open shots? His volume is low, but he's hitting almost 44% of his wide-open 3's since New Year's Day. Those are the looks opponents are going to give him, and they're the reason the Cavaliers rank 19th in the NBA in clutch offense. Thus far this season, they haven't been able to find a fifth player that can survive defensively without gumming up their late-game offense. If they're going to make a deep run this season, Okoro has to be that player. 

5. New York Knicks

The lineup: Jalen Brunson, Immanuel Quickley, Quentin Grimes, Julius Randle, Isaiah Hartenstein

Total possessions this season: 225

Net rating this season: +15.3

For the first time in the Tom Thibodeau era, the Knicks are actually getting legitimate production out of their starting lineup. The Elfrid Payton-led 2021 unit was outscored by 4.4 points per 100 possessions. Last season's Kemba Walker-led starting five somehow managed to start 24 games despite getting outscored by 13.4 points per 100 possession. But this year? The starters have a plus-7 net rating. That's pretty good! But, like most things where the Knicks are concerned, it gets better with Immanuel Quickley.

In three seasons as a Knick, Quickley has led the team in plus-minus twice and finished in second once. He is currently a cool plus-266 in 2,170 minutes, and a brief look at the lineup data makes it clear who Quickley should be replacing when it counts.

  • When Quickley and R.J. Barrett play together, the Knicks are average.
  • When Barrett plays without Quickley, the Knicks are outscored by 2.4 points per 100 possessions.
  • When Quickley plays without Barrett, the Knicks outscore opponents by 11.2 points per 100 possessions.

To some extent, this is a fit issue. Maximizing Barrett theoretically means giving him the ball more than a team with Brunson and Randle wants to. Quickley is the better shooter and defender, and he introduces a layer of pace that a team that frequently uses two big men needs. The last time Barrett played in the playoffs, he shot below 40% from the field.

The Knicks could go in a number of directions beyond Brunson, Quickley and Randle. Virtually every Josh Hart lineup has been excellent, but again, with two big men, the Knicks come with specific demands out of their smaller players. The superior shooting of Grimes probably earns him a slot here. In theory, the Knicks could just play Quickley with their four other starters, but he's developed a stronger chemistry with Isaiah Hartenstein this season. That duo is outscoring opponents by 11.9 points per 100 possessions, whereas the Quickley-Robinson pairing is at just 3.1 points per 100 possessions.

Randle's sprained ankle throws a wrench into these plans. For now, we'll assume he's healthy. If not? We're probably going to see more of Obi Toppin. Thibodeau has played Barrett just 139 possessions at power forward this season. It's a look worth exploring, but it goes so far against Thibodeau's stylistic preferences that it likely won't get much of a chance.