On the surface, the 2020 NBA title chase is three teams deep.

The two Los Angeles teams are there as expected, and the Milwaukee Bucks’ obscene regular season means they cannot be ignored in any serious discussion trying to project the champion.

The next tier, by this theory, includes half a dozen or so other interesting teams that are considered to be fatally flawed, one big piece short, or both. The latest Vegas futures bear this out: The top three teams are tri-favorites in the betting, and there’s a group of seven well behind them, but well ahead of 12th-place Dallas.

It’s hard to go against Vegas, but I’m going to do it anyway. There’s a fourth team that belongs in that top tier: the Boston Celtics.

Probably not the team you expected, right? The Celtics had the ninth-best title odds as of the all-star break, behind five teams (Clippers, Houston, Denver, Philadelphia, and Utah) with worse records. FiveThirtyEight likes the Celtics a bit better, but still gives them only a 16 percent shot to win the East and a five percent shot to win the title, well behind the 76ers and Rockets. (The site’s Elo Rating likes Boston’s chances even more, though not as much as Toronto’s). I suspect the Celtics are still being downplayed because of their decision to rely on addition by subtraction when Kyrie Irving and Al Horford left in free agency.

But that decision has paid off. The Celtics are much more dangerous than last year and should be taken more seriously alongside the other clear championship contenders. Here’s the six-step case for Boston:

1. The fundamentals check out

Here are some key numbers:

Boston’s net rating (i.e., the difference between their offensive and defensive ratings) is +6.8. That’s third in the league behind Milwaukee (miles ahead) and the Lakers (barely ahead). It’s better than Toronto, more than a full point better than the Clippers, twice as large as Houston and Miami, and nearly three times as big as Philadelphia.

That’s third in the league behind Milwaukee (miles ahead) and the Lakers (barely ahead). It’s better than Toronto, more than a full point better than the Clippers, twice as large as Houston and Miami, and nearly three times as big as Philadelphia. They rank in the top-five in both offensive and defensive rating (points scores/allowed per 100 possessions): Again, only Milwaukee and the Lakers can say that.

Again, only Milwaukee and the Lakers can say that. They are a top-12 team in seven of the eight key factors for winning (Four Factors on offense and defense): No other team can say that.

No other team can say that. They are 13-9 against the other 13 teams that have .500 or better records: Their point differential in those games: +4.5. Only the Bucks, at 12-7, have a better winning percentage against over-.500 teams, but their point differential in said games is actually worse (+4.4). (As an addendum: as Nylon Calculus’ Krishna Narsu points out, Boston still ranks tops in point differential against teams with positive net ratings, which excludes Memphis. However, they drop to third behind Milwaukee and Denver in winning percentage).

All that despite a litany of nagging injuries that have prevented the Celtics from seeing their best team on the court consistently. The quintet of Jayson Tatum, Kemba Walker, Gordon Hayward, Jaylen Brown, and Marcus Smart — clearly the team’s five best players irrespective of position — has only been active together for 15 of a possible 54 games this year. (I’m not counting the November game in San Antonio when Hayward went down after 14 minutes due to injury).

2. Jayson Tatum is making the leap

Michael Pina covered this topic well, as did The Ringer’s Rob Mahoney. I don’t have much more to add. I’ve been a longtime Tatum skeptic, but I’ve seen enough material improvement with his weaknesses to change my tune.

3. They have so many ways to score. Thank Kemba Walker

Tatum’s ongoing rise into a capable top scoring option when all else fails is crucial because the Celtics have the rest of the offense down to a T. Between Tatum everywhere, Walker in pick-and-roll, Hayward off the catch, Brown in transition, and Brad Stevens’ excellent set play diagramming, the Celtics have so many different ways to create offense. Unlike last year, they’ve integrated each of those threats into their overall attack without suffering from the pecking order issues that made their mix much less than the sum of its parts last year.

One major reason: the switch from Kyrie Irving to Kemba Walker. (Go ahead and gloat, Celtics fans. You were right about this).

When the Celtics acquired Walker, I was worried they were simply swapping out one ball-dominant, pick-and-roll heavy point guard for an inferior (albeit nicer) version. Instead, Walker has demonstrated an ability and willingness to play off the ball that he never got a chance to show in Charlotte. Pick-and-roll is still his bread and butter, but he’s also getting shots in other ways. This transition pindown is a Celtics staple.

Boston will also use Walker as a screener before popping him out for open shots.

But even the many pick-and-rolls Walker does run are of a different character than the ones he used in Charlotte. He’s giving the ball up and getting it back on the move, which keeps the Celtics’ other key playmakers involved and maintains the offensive flow needed to balance touches elsewhere.

Irving is a better shooter, scorer, and finisher. Full stop: he’s a better player. But Walker is, in a way, more exhausting to defend. His movement forces all five defenders to make more coverage decisions. Because of that, Tatum, Hayward, and Brown can attack from more dynamic and advantageous positions, which helps Boston’s offense as a whole. By working more within the system instead of as a solo artist, Walker provides more structure for other Celtics attackers that need a bit of a head start to activate their gifts.

More fundamentally, Walker simply does less than Irving. Less dribbling, less yo-yoing with the ball, less time to make his move, less standing, and, of course, less shooting. That’s led to more opportunities for Brown, Hayward, and Tatum — and, in turn, more threats for the defense to address.

That improved balance plays out in two ways. For one, it allows Stevens to more easily dial up set plays with multiple actions that flow seamlessly into each other. He can use any combination of his four top offensive players as decoys, primary options, screeners, floor-spacers ... you name it. When the execution is sound, you get beautiful stuff like this, where the Raptors aren’t sure to focus more on a potential Walker dribble-handoff or the Hayward ball screen that leads to an open three.

It also makes Boston increasingly difficult to defend in crunch time when all four key offensive players are on the court. There’s nowhere for a bad defensive player to hide, and Boston will ruthlessly punish those players using a diverse array of two-man screening actions. The Celtics may not have a gifted scorer like Irving to get tough playoff buckets against the best individual defenders, but pitting any combination of their four top options against the opponents’ worst defender often yields a better result anyway.

Recent crunch time successes against the Thunder and Clippers illustrate the cat-and-mouse game the Celtics are equipped to win in tight playoff games. Against the Thunder, the Celtics targeted Danilo Gallinari down the stretch, using three different players on three straight possessions to screen for Walker to get the ideal matchup. Boston scored all three times.

The double-overtime victory over the Clippers was certainly Tatum’s coming-out party, but Boston made his life easier by constantly attacking Lou Williams and Landry Shamet.

Those weak defenders can avoid the switch with a hard hedge and recovery back to their original men. In the playoffs, they’ll work harder to do that and avoid mismatches. But unlike teams built around one great scorer, Boston has multiple players they’ve empowered to make plays off a closeout. That allows the Celtics to target a weak defender’s one-on-one and help defense at the same time.

Walker’s size is an issue against traps, which will be much harder in a playoff setting. However, Tatum’s emergence mitigates the need to rely on Walker to do everything, and Walker’s temperament allows him to more easily slide into second option status.

Doing so should also give him more energy to compete defensively, where he hangs in there decently despite his lack of size. Teams will target Walker in the playoffs the same way the Celtics target opponents’ worst defenders. But Walker is quick, tough, and aggressive, making him closer to an average defender like Stephen Curry than a total sieve like Trae Young or, crucially, Irving.

Ultimately, swapping out Irving for Walker has made Boston’s offense more dynamic as a whole. The subtle differences between the two ensure that the Celtics’ multi-playmaker structure adds up to more than the sum of its parts.

4. They win the chaos sequences

There’s a common perception that teams which thrive in transition struggle in the playoffs because tempo generally slows down. At the same time, the more controlled pace of the postseason means unscripted moments like fast breaks, hustle plays, early offense attacks, and other moments within the run of play have even more comparative value. The last two NBA champions (Warriors and Raptors) made a living out of maximizing these “chaos” opportunities.

The Celtics aren’t the most dangerous team “chaos” team in the league — I’d give that honor to Toronto, with Milwaukee close behind — but they’re pretty close. They have two players to thank for that: Marcus Smart and Jaylen Brown.

Smart’s capacity to make “winning plays” is obvious. Anyone who’s watched even a few seconds of Celtics basketball since 2014 understands his knack for coming up with critical loose balls, offensive rebounds, and defensive stops against bigger players. When defensive sequences break down, his instincts take over and constantly throw off the other team. He happily switches onto speedy guards, sleek wings, or rugged big men, especially in high-leverage situations. His closeout techniques are occasionally unconventional and often hilarious, yet effective. There’s a reason opposing players have shot below their average on three-pointers Smart defends for four years running, according to NBA.com’s tracking data.

Meanwhile, Brown has become one of the league’s most effective transition playmakers. He’s third in the league in fast break points per 100 possessions, trailing only Giannis Antetokounmpo and (barely) LeBron James. The Celtics score an average of 1.2 points per possession off missed shots with Brown on the court and 1.4 points per possession off steals, both significantly higher marks than they score in said situations with Brown on the bench.

Brown’s athleticism and burgeoning craft in the open floor allows Boston to strike quickly. He’s strong enough to power through even the stingiest transition defensive walls to score.

Yet he’s also smart enough to manipulate odd-man breaks or advantageous matchups to get high-percentage early-offense looks for himself or his teammates. His handle has improved, and he’s become more comfortable decelerating and then pivoting in the lane for more difficult two-footed finishes.

Together, Smart and Brown help ensure the Celtics compound opponent mistakes and missed opportunities with buckets of their own. One creates chaos, and the other capitalizes on it.

5. They have enough up front

Put some respect on Daniel Theis’ and Enes Kanter’s names! They might not be the duo most teams would go to war with, but they are ideal complements for Boston’s style of play

Both are terrific screen-setters on or off the ball, an essential quality in Boston’s perimeter-heavy attack. Theis in particular is a master of the “double screen” tactic on pick-and-rolls — often known as “the Gortat” after the former Wizards center who pioneered the move. Watch as Theis sets a normal ball screen on Wes Matthews, then rolls down the lane to then seal off Brook Lopez from helping on Tatum’s drive.

Theis is also an underrated pick-and-roll defender and defensive rebounder. You rarely see him caught out of position, which also helps the Celtics end possessions effectively with defensive rebounds. He also does enough to keep the defense honest from the perimeter, as well as in 4-on-3 situations after his man traps ball-handlers. There’s a reason the Celtics’ starting lineup of Brown, Walker, Hayward, Tatum, and Theis outscore opponents by more than 14 points per 100 possessions.

Kanter, meanwhile, comes off the bench to provide a much-needed different dimension. His pick-and-roll defensive struggles are well known, but he makes up for it with relentless offensive rebounding, a key mode of attack the Celtics lacked last season. Boston snags a whopping 33 percent of their their own misses with Kanter on the floor, a mark that’d lead the league by more than three points if maintained over 48 minutes. His glass work is even more devastating because the Celtics perimeter players already put defenses in rotation all the time with their combined playmaking.

Kanter’s offensive rebounding ability also makes him a deadly weapon if opponents try to confuse the Celtics with a zone defense. He’s adept at slipping into the right soft spots in the paint for layups, and good luck putting a body on him when someone else shoots.

There are certainly problematic matchups for these two. (Joel Embiid and the Philadelphia 76ers have entered the chat.) But they’ve held their own in the regular season, and there’s little reason to believe they can’t do so again in most playoff scenarios.

6. Their rotation will shorten in the playoffs

Depth is Boston’s biggest weaknesses, especially once you get past the four lead playmakers, Smart, and the two centers. Brad Wanamaker has been a reliable backup point guard and rookie Grant Williams offers an intriguing defensive skill set, but teams will help off both to shrink the floor in the postseason. We already know Semi Ojeleye can’t shoot, though he can at least bug Antetokounmpo for a few minutes. Robert Williams is a total unknown, as is Vincent Poirier. Romeo Langford and Javonte Green have been intriguing in limited minutes, but I need to see more. There’s also Tacko Fall, and ... nope, it’s not happening.

But rotations shorten in the playoffs, especially for teams like Boston that can use their front-line players to prop up bench units. It’d be nice if the Celtics had one more reliable rotation player, but they should be able to get by even if just one of the above players can pop in any given game. After all, one positive to all the injuries to the starters is that they’ve given these young bench players more experience in the regular season.

So yes, depth is certainly an issue, especially compared to Milwaukee’s bench mob. But the Celtics should be able to compensate in the playoffs if they dial up their starters’ minutes.

Ultimately, the biggest case against Boston is simple: they don’t have LeBron James, Giannis Antetokounmpo, Anthony Davis, or Kawhi Leonard. Tatum is emerging as a superstar, but he’s not on that level and may never be. Perhaps that’s all you need to hear to downplay Boston’s chances.

But outside of that, Boston has all the bona fides of a true title contender. They win consistently by a lot, they regularly beat good teams, and they are balanced on both sides of the ball.

In a transitional year like this that lacks a dynastic team like the Heatles or Light Years Warriors, the Celtics have as much as shot as any of the three more obvious favorites. Dismiss them at your own peril.