What’s Fueling the Celtics Resurgence Down the Stretch?

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By MacBell

Apr 11, 2021; Denver, Colorado, USA; Boston Celtics center Robert Williams III (44) and forward Grant Williams (12) and forward Jayson Tatum (0) and guard Jaylen Brown (7) and guard Marcus Smart (36) during the fourth quarter against the Denver Nuggets at Ball Arena.

The Boston Celtics have had a less than ideal season so far. Their struggles were the result of not one but many problems on both sides of the court. But they are 8-2 in their last 10 games, and their 6 game win streak is currently the longest in the NBA (tied with the Knicks). So far in April, they’ve found a new form and are flying up the eastern conference standings. So, what’s the cause of the Celtics’ resurgence?


Apr 11, 2021; Denver, Colorado, USA; Boston Celtics forward Grant Williams (12) blocks the shot of Denver Nuggets center Nikola Jokic (15) in the fourth quarter at Ball Arena.
Ron Chenoy-USA TODAY Sports

For Brad Stevens’ Celtics teams, it always starts and ends on the defensive end. In their last two eastern finals runs, they had top 5 defensive ratings in the regular season. It’s always been the defense bringing them to great heights. But this year, things have been different.

They’re currently tied for the 13th defensive rating in the league. That is wellWELL below where this team should be. The roster is nearly identical to last year minus Gordon Hayward, yet they’ve taken a huge leap backward on defense. Remember, this isn’t the Nets or the Nuggets. They don’t have the sheer offensive firepower to overcome a mediocre defense.

Throughout the season, the defense has been the biggest and most consistent problem. The most frustrating part? At times they would play elite defense for short stretches. The problem was never that this team couldn’t defend; it’s that they weren’t defending. But as of now, those defensive issues are in the past.

In April, the Celtics have the 6th best defensive rating in the league. Yeah, that’s more like a Brad Stevens team. This season the Celtics have held teams below 100 points 6 times; 3 of those occurred this month.

Their most impressive defensive showing, probably in the whole season, came against Denver on April 11. Down by 14 with 2 minutes left in the third quarter, the game felt close to out of hand. But something happened; instead of folding like they have too many times this season, they met the challenge. They played stellar defense, and the Nuggets couldn’t score another field goal for the next 7 minutes. By that point, the Celtics had stormed back to tie the game. They proceeded to hold the Nuggets to 8 points in the fourth and won handily.

The defense coming together for this Celtics team is so important. When it comes to the playoffs, they can only go as far as their defense takes them.

Staying Healthy

It feels like the Celtics have not had a full roster for one game this season. Kemba Walker and Romeo Langford both missed extended time to begin the season. Once Kemba returned in January, Marcus Smart injured his calf and didn’t return until after the all-star break.

Feb 2, 2021; San Francisco, California, USA; Boston Celtics head coach Brad Stevens gestures from the bench during the second quarter against the Golden State Warriors at Chase Center.
Darren Yamashita-USA TODAY Sports

These injuries impacted the Celtics in a greater way than simply losing individual games. They haven’t had enough time together to figure things out, and it really showed this year. Their defensive issues were largely due to miscommunications, and the offense looked plain broken at times. The effects of all their players missing time can’t be understated.

Injuries haven’t been the only ailment plaguing the Celtics roster this year. The COVID-19 Health and Safety Protocols have been an issue for Celtics players all year long. Fansure has been tracking how players and teams have been affected by the Health and Safety Protocols this season. As of their last update (April 11), the Celtics are by far the team impacted most. They’ve missed 137 player days due to H&S Protocols.

All season the Celtics have been missing somebodies. Sometimes a lot of somebody. They’ve used 25 different starting lineups throughout 57 games. But over the last few weeks, the roster is getting closer to full strength. Unsurprisingly, things are starting to click for them. The (theoretical at times) starting lineup post-trade deadline has been Kemba, Smart, Brown, Tatum, and Robert Williams. They’ve gone 6-1 with that lineup. Getting healthy has played a key part in the Celtics’ resurgence. Health has affected this team all season long. But as that has become less of an issue, the wins have started to pile up.

Ball Movement

Apr 15, 2021; Los Angeles, California, USA; Boston Celtics forward Jayson Tatum (0) controls the ball as center Tristan Thompson (13) provides coverage against Los Angeles Lakers guard Alex Caruso (4) during the first half at Staples Center.
Gary A. Vasquez-USA TODAY Sports

The Celtics have been a low-assist team for a while now. On the season, they are 23rd in the league in assists per game. For some teams, this works. They run heavy isolation or pick and roll on offense. They hunt mismatches and let their best players go to work. You’re probably thinking, “Well, the Celtics have Tatum and Brown; a high isolation offense sounds awesome with those two guys, right?” Theoretically yes. But so far this year, they haven’t been amazing ISO players.

According to the NBA’s advanced metrics, Tatum ranks in the 43rd percentile for isolation plays, and Jaylen Brown ranks in the 30th. If you can’t tell, that’s low, like really low. Jaylen Brown is well below the league leaders in ISO frequency, but Tatum is 10th in the league. Considering their efficiency on isolations, both these guys should be doing it a lot less. They can both get a bucket, don’t get me wrong, but that should be reserved for extremely late-game situations or as a bailout on broken possessions. Not as a primary or secondary option in the middle of games.

If we look at the team in general, the numbers don’t get any better. The Celtics are 9th in the league in ISO frequency but 26th in scoring frequency on those plays. Isolation isn’t an efficient way for this team to score. Tatum, Brown, and Kemba are all good offensive players who can get a bucket when needed, but the rest of the team isn’t. That’s what makes isolation plays so bad for this team. The other guys on the team aren’t elite offensively, which allows defenses to close in on whoever has the ball and make life tough for them.

Isolation isn’t the right direction for this team. They need significantly more ball and player movement. That will not only create better looks for some of the other guys on the team. It will open the game up for Tatum, Brown, and Kemba. Over the last month, we’ve seen much more of that.

The Celtics as a team make 297.7 passes per game and averaged 26.4 assists per game in April. Both of these numbers are 10th in the league. That’s well above their season averages of 287.7 passes per game (15th in the league) and 23.4 assists (23rd in the league). These passing numbers are extremely encouraging. It can be hard to break out of a static offense. The more motion in an offense, the harder it becomes to execute. But the Celtics are doing exactly that. They’re putting more effort in on offense and reaping the rewards.

They have the 5th best offense in the NBA so far in April. That’s not a fluke; the uptick in ball movement has improved their offense. Every team plays to its strengths. For this team, that means ball movement and lots of it. That’s what is giving defenses the most trouble and helping the Celtics’ resurgence.

Other Factors

I’ve already gone over the 3 big reasons for the Celtics’ resurgence; getting healthy has allowed this team to perform better on defense and offense. That’s why their record has improved. But some smaller things happening in the background are also helping this Celtics team.

Jayson Tatum

Apr 11, 2021; Denver, Colorado, USA; Boston Celtics forward Jayson Tatum (0) shoots the ball over Denver Nuggets forward Will Barton (5) in the fourth quarter at Ball Arena.
Ron Chenoy-USA TODAY Sports

OK, I said that these would be some other quiet things in the background, but Jayson Tatum has been anything but quiet recently. After winning Eastern Conference Player of the Week last week, he’s played well enough to win again this week.

Similar to the 2019-20 NBA season, Tatum has made a big jump in his play after the all-star break. According to Statmuse, he’s averaging 27.6 points, 7.3 rebounds, and 3.9 assists per game.

The most impressive part of his game lately? His increased drives to the rim. For example, we can look at the Celtics’ recent game against Golden State. Which also may have been the best game of the season so far. Tatum had 44 to match Stephen Curry’s 47. Seeing Tatum duel Steph says a lot about his current place in the league.


Early in the season, Tatum settled for jumpers far too often, especially considering how much he’s improved as a finisher at the rim. In this game, we see what he’s been doing lately: relentlessly attacking the basket. The plays that say the most about his improvement are when he gets switched onto Kevon Looney, the Warriors center.

For his whole career, Tatum has been content to take stepback 3’s against opposing centers. Not that those don’t work but getting to the rim is more efficient in that situation. You can see Looney switch out at the 0:57 mark of this video, and Tatum drove right by him for a layup. For anybody who’s watched the Celtics all year, that play is a stark contrast to what usually happens. But it’s the right choice from Tatum and one that he’s been making with much more frequency.

Tatum’s jump has been significant for the Celtics’ improvement of late. This isn’t to say their other stars haven’t been great. All four of Tatum, Brown, Kemba, and Smart have reached a new level recently; Tatum has just been the loudest.

A Second Half Team?

Apr 13, 2021; Portland, Oregon, USA; Boston Celtics point guard Kemba Walker (8) controls the ball against the Portland Trail Blazers during the second half at Moda Center.
Soobum Im-USA TODAY Sports

You may remember the Celtics being blasted earlier in the season for their terrible 4th quarter performance. They allowed other teams to win 4th quarters by large margins and struggled to close out tight games. Well, it seems like the Celtics have shored up those problems.

The most obvious example is the 4th quarter thrashing of the Denver Nuggets I mentioned earlier, but it’s not just that game. They’ve won the 4th quarter in 7 of their 9 games here in April, as well as winning the OT period against Minnesota. They’re 5-0 in clutch games this month, which accents their ability to close out games.

After a close win against the Knicks, many on the team said it was one of their best wins all season. It wasn’t their greatest night, but they found a way to win. These are the kind of wins that great teams can get.

“That’s one of our better wins on the year all things considered, because of the way that our guys had to figure out a way to win.”

Brad Stevens after the Celtics defeated the Knicks

All of this great play to close out games has the Celtics’ 4th quarter rating climbing. They are 7th in the league in 4th quarter net rating after the all-star break.

Ask Celtics fans about the team, and they’ll probably mention the tendency to get behind early in games. They take it slow in the first and second quarter, then claw back in the second half. It’s not a good way to go about things, but it’s how they’re doing it so far. The surprising part: It’s kind of working.

Post-All-Star break, the Celtics are tied with the Jazz for the best 2nd half net rating in the league. That’s mainly a result of their league-leading 2nd half offense in the same time frame. Getting behind in games isn’t great, but if you’re the best 2nd half team in the league? It’s kind of OK.

Looking to the Playoffs

Apr 7, 2021; Boston, Massachusetts, USA; Boston Celtics guard Jaylen Brown (7) goes in for a dunk against the New York Knicks during the fourth quarter at TD Garden.
Winslow Townson-USA TODAY Sports

So, the Celtics are good now? Yes, if they keep this up, they’re a lot closer to the team that made the eastern conference finals last year than they are to the team we’ve seen most of this year. But before thinking about the playoffs, you have to get there.

It’s hard to predict the final seeding because the eastern conference is so tight. If the Celtics keep playing well, they can secure the 4 or 5 seed. With a clear top 3 in the east (76ers, Nets, Bucks), staying clear of the 6 seed is important. This avoids a first-round matchup with any of the 3 powerhouses.

It’s important that the Celtics’ resurgence has occurred before the playoffs. It’s always risky hoping that you can pick it up a level during the playoffs, especially when you’re as young as this team is. The last two weeks have shown what this team is capable of, and they’re not even full strength yet. Getting Evan Fournier back can unlock even more offense from this team and make them truly elite.

When it comes to the playoffs, anything can happen, of course, but if the Celtics are firing on all cylinders, they could make a deep playoff run. The league is full of dominant teams, but they feel like a bit of a sleeping giant. Maybe the Celtics’ resurgence is just a sign of them waking up.

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