NBA Playoffs 2020: 4 biggest questions for the Eastern Conference Finals

Heat vs. Celtics is the Eastern Conference Finals matchup no one expected. These are the lineup, matchup and strategic issues that will decide a winner.

The Eastern Conference Finals are finally set, and the matchup is a familiar one: Celtics vs. Heat. These two franchises met in the playoffs in 2010, 2011, and 2012, though obviously the participants in those games were markedly different than the ones that will decide this series. Virtually the only thing that is the same about either of the two teams is that the Heat are still coached by Erik Spoelstra and Udonis Haslem is still hanging around on the end of Miami’s bench.

The two squads that actually take the floor to vie for the right to represent the Eastern Conference in the NBA Finals will also look markedly different than they have for any of their previous three matchups this season. The two pre-hiatus matchups between Boston and Miami each took place before the Heat traded for Andre Iguodala and Jae Crowder. The Heat were still starting Meyers Leonard at that point, plus Goran Dragic missed the first matchup and then-starter Kendrick Nunn missed the second. Justise Winslow was heavily involved defending Boston’s stars in the first of those two matchups, while Marcus Smart didn’t dress for the first game and Jayson Tatum didn’t suit up for the second one.

Even the teams’ third matchup, which took place in the bubble, is unlikely to tell us much about the forthcoming series. Kemba Walker was on a minutes limit, Marcus Smart saw only 15 minutes, Jimmy Butler didn’t play at all, and the game took place before Miami pulled Nunn and Kelly Olynyk from the starting lineup in favor of Dragic and Crowder. For all three of those games, by the way, the Heat were playing the second game of a back-to-back.

All these changes and the relative lack of relevant prior matchup data leave us with a host of unanswered questions. Let’s dig into a few of the underrated ones that might help tip the balance of the series.

How much zone defense will the Heat play?

Teams played zone against the Celtics fairly often during the regular season. They saw 289 possessions of zone defense, fourth-most of any team in the league, per Second Spectrum. Among the 20 teams that faced at least 100 possessions of zone, Boston ranked ninth in offensive rating, and a peak further under the hood reveals their quantified shot quality (qSQ: Second Spectrum’s metric for expected effective field goal percentage) ranked eighth.

But the Celtics struggled pretty badly with the Raptors’ zone defenses in the last round. Toronto utilized a zone on 80 defensive possessions, per Second Spectrum, with the Celtics scoring only 65 total points on those plays. The zone helped the Raps force the Celtics to go deeper into the shot clock than usual, with possessions lasting an average of 17.4 seconds, compared to 15.7 on non-zone possessions and 14.5 during the regular season on the whole.

Which team used zone defenses more than any other during the regular season? The Heat, who did so on 11.1 percent of their defensive possessions. They also employed it quite often against the Celtics. Though the Heat didn’t use their zone at all in the first matchup between the two teams, they threw it out there for 28 possessions in the second matchup and 33 possessions in the third. The Celtics did not manufacture particularly good shots against Miami’s zone in those games, and it would not be surprising if Spo turned to it quite often during this series.

Miami is set up a bit better to deal with Boston’s big wings than Toronto was, given the presence of Jimmy Butler, Jae Crowder, and Andre Iguodala, but if the Heat want to cut off Kemba Walker’s penetration without having to use Butler on him for long stretches, the zone might be the way to go.

What’s the deal with Gordon Hayward?

Hayward has been out since Game 2 of the Celtics’ first-round sweep of the 76ers. He sprained his ankle pretty badly and was expected to miss four-to-six weeks, and we’re coming right up on the four-week mark pretty soon. Hayward got some shots up before the last game, but Brad Stevens would only allow that he expects Hayward to return at some point during the series against the Heat, without specifying when.

During Hayward’s absence, the Celtics have used a starting lineup of Kemba Walker, Marcus Smart, Jaylen Brown, Jayson Tatum, and Daniel Theis. That group was plus-10 in 126 minutes against Toronto and it was plus-13 in 148 regular-season minutes. The same unit with Hayward subbed in for Smart was plus-52 across 262 regular-season minutes, giving it a significantly better point differential in similar playing time. So, will the Celtics slot Hayward back into his usual spot, or will they keep Smart there?

There are merits to both sides of the argument. Matching Smart’s minutes with Jimmy Butler’s makes a lot of sense, for example. Smart is the team’s best overall defender, and in the one Celtics-Heat game that both players played, it was Smart that spent the most time on Butler. The Heat scored just 21 points on 27 half-court possessions, with Butler himself shooting 1-4 on heavily contested looks and with the Heat putting together some pretty ugly possessions.

But Smart didn’t match Butler’s minutes, and the Celtics seemed just as comfortable defending him with Hayward (17 possessions) or Brown (14), who did just about as good of a job. It seems less bankable given what we know about all three players, but the gap in offensive results between the Smart lineup and the Hayward lineup, though, Stevens could just as easily decide he’s better off going back to his usual starters.

Of course, that assumes Hayward is all-systems-go at some point during the series. Given how much time he’s missed, it’s entirely possible he returns on some sort of minutes limit, in which case it might make more sense to use him as a captain-of-the-bench-unit type, to carry some of the scoring load when Walker and/or Tatum are on the bench.

Who is Boston’s backup center for this Eastern Conference Finals?

We pretty much know the Heat’s rotation. Dragic, Butler, Duncan Robinson, Crowder, and Bam Adebayo will start, and with the exception of Robinson (and maybe Crowder, more on that in a minute), they’ll all likely play 30-plus minutes. Tyler Herro is the first guy off the bench, and he’s in the closing lineup as well. Andre Iguodala and Kendrick Nunn will handle the other reserve minutes on the perimeter, with Iguodala potentially playing more in this series than he did in the last one, when he got only 16.2 minutes per game. And Kelly Olynyk is the backup center, for around 12-13 minutes a night.

In the first round, Boston largely used Enes Kanter as the backup center, the better to combat Joel Embiid’s size. Kanter got 61 minutes across four games. Grant Williams saw the floor whenever Al Horford was the lone big man, taking up 18 backup center minutes. The Time Lord, Robert Williams, saw only total 22 minutes across three appearances.

But against Toronto, Stevens switched things around. This time, Robert Williams was the primary backup center, with his athleticism necessary against Serge Ibaka and an advantage against Marc Gasol. He got 100 minutes across the seven-game series, while Kanter appeared only twice for eight total minutes. Grant Williams saw 81 minutes of floor-time, but 26 of those were next to Theis, 24 were next to Time Lord, and five were with Kanter. That left 26 minutes as the center, including some crucial ones down the stretch of Game 7, while the Raptors were in their small-ball look with Pascal Siakam at the 5.

So, how will Boston choose to match up with Olynyk? That doesn’t seem like the optimal matchup for Kanter, and while his size could be useful against Adebayo at certain points, he could be severely out-matched in the lateral mobility and quickness departments. Time Lord would have a major athleticism advantage over Olynyk, but also isn’t quite as comfortable guarding on the perimeter, where Grant Williams would likely be a better fit. Grant would probably be overwhelmed physically by Adebayo, though, making Robert a better fit for that matchup whenever Theis is on the bench.

Who closes: Iguodala, Crowder, or both?

In the Heat’s opening-round series against the Pacers, their preferred closing group included Dragic, Herro, Butler, Iguodala, and Adebayo. Prior to the postseason, that quintet had played precisely zero minutes together. But they played 27 minutes in that series, each and every one of them in the fourth quarter, out-scoring the Pacers by 10 points in that time.

Fast forward to the Bucks series, and that group played … one minute together across five games. Instead, the closing unit included Crowder in Iguodala’s place. That five-man unit played 33 minutes in the five-game series, smashing the Bucks by 25 points in that time. How much of that was matchup-based? How much of it was due to the ankle injury Iguodala suffered in Game 2? How much of it was Crowder’s ridiculously hot shooting? (He went 22-51 from three in the series.)

Down the stretch of games in the Celtics series, we can damn near guarantee that Dragic, Butler, and Adebayo will be on the floor. The other two spots seem more up in the air. Herro has earned the right to be out there with his play, but he’s also the most likely of the three possibilities to be physically over-matched against Boston’s wings. Iguodala is probably the most dependable individual defender, but he’s easily the weakest shooter and that could be an issue against the Celtics. Crowder brings the best size-shooting-defense combination of the three, but he also runs extremely hot-and-cold from outside and is a better matchup for power wings than silkier ones.

It might make sense to have Crowder on Brown and Butler on Tatum; but then who guards Hayward, if he’s in the game? And do you trust Dragic on Kemba? Do the Celtics have it in them to repeatedly target Herro, and if they do, is he up to the challenge? The Heat mostly used Crowder on Tatum and Bam on Brown when these two teams played during the seeding games, but again, Butler didn’t play in that one, plus Walker was on a minutes limit and Iguodala spent more possessions on Semi Ojeleye — who is unlikely to factor heavily into this series — than any other Celtic.

How Spoelstra chooses to close will tell us how he sees this matchup, and what he thinks is most important to take away the Celtics. The answer to that question might depend on Stevens’ answer to one about Smart and Hayward.