As we cross the one-quarter mark of the NBA season — with the Clippers in first place out West, the Kings playing .500 ball, and the Jazz and Rockets near the bottom looking up — things are starting to come into clearer focus. That clarity is more than welcome, given how topsy-turvy the league has been for the first month and a half of play.

We know a lot will change between now and April, but for the time being, here are the five things we’ve been most and least surprised by so far this year.

Surprising: The Celtics haven’t been good, and the Jazz have been even worse.

Boston, finally healthy after losing two of its best players last year, has been one of the bigger mysteries of the season. The Celtics have been elite defensively again this year, but the offense — which almost never gets to the line — can’t get out of its own way much of the time.

Before the season began, Jaylen Brown expressed a belief that the starting wings (him, Gordon Hayward and Jayson Tatum) have nearly identical skill sets, which was affecting chemistry. And after watching them for a month and a half, we can’t say that he was wrong. With that in mind, Brad Stevens’s recent lineup shift to bring the struggling Hayward off the bench could help matters.

Hayward and Brown, in particular, have both shot far better from the floor when playing apart from each other. Hayward sports a solid 53.9 percent effective field-goal rate without Brown but just 39.7 percent with him. And Brown’s 50.5 percent effective field-goal rate without Hayward is well above the 38.5 percent mark he posts while sharing the court with Hayward.

Their net ratings also improve when playing apart. The Celtics outscore opponents by 9 points per 100 possessions with Hayward but without Brown, and Boston wins by a margin of 1.5 points per 100 when Brown is on the court but Hayward is on the sideline. But the Celtics hemorrhage 2.2 points per 100 possessions with the two playing together.

Using floor-spacing forward Marcus Morris as a starter may work better because of his rugged screen-setting ability. His off-ball screens, useful for a lineup with so many scoring options on the wing, produce the best scoring efficiency of any player on the team at 1.12 points per possession when both Tatum and Hayward are on the floor and a whopping 1.53 points per possession when Tatum and Brown are playing together, according to Second Spectrum.

It’s also worth keeping an eye on Terry Rozier, who, to this point, has regressed badly on the offensive end after a highly encouraging postseason run, in which he filled in admirably for the injured Kyrie Irving.

As for the Jazz, this — 10-12, and third-to-last in the West — is what happens when your league-best defense from last season is merely a middle-of-the-road one, and your offense not only fails to improve but actually morphs into one of the NBA’s five worst in that same window.

What’s behind Utah’s slide? A handful of theories have been discussed. But two things stand out to me: 1) The team’s schedule — the toughest in the league — has been front-loaded, and 2) a number of players aren’t playing to their capabilities.

Outside of a one-week stretch at the end of October, Donovan Mitchell has been terribly inconsistent, struggling badly from outside. Dante Exum’s offense still isn’t catching up to his defense. And perhaps the biggest issue: Ricky Rubio has been awful on both sides of the ball thus far — even more than he was to start last season, when he had just joined the club and was learning the ropes.

Rubio has generally been able to hang his hat on his defense and his passing whenever he’s struggling to shoot. But this season, he has sometimes looked a half-step slower laterally on D, allowing nearly a 10th of a point more per drive he defends, at 0.98 points per play, than he did last season, according to Second Spectrum. And while opponents have long sagged off Rubio, daring him to shoot, that experiment has paid far greater dividends this season, as he’s logged just a 46.6 percent effective field goal rate on jumpers when given 6 or more feet of open space — down from 53.5 percent just last year, and the worst percentage he’s connected on since the 2013-14 campaign, according to NBA Advanced Stats.

It’s still a little early to consider changing the lineup — especially after Rubio played so well at times last postseason. But if he doesn’t turn it around in the next month or so, it might be worth trying a new starting five and letting Mitchell handle the ball more. (Utah, realizing it needs more punch on offense, traded guard Alec Burks and two future second-rounders Wednesday for sharpshooter Kyle Korver.)

We wrote this summer that we believed the Jazz could be true contenders this season — which looks incredibly wrong at the moment. But we said then that much of Utah’s hopes would hinge on Rubio’s play. For better or — to this point — perhaps for worse, that seems to be the case.

Not surprising: The Grizzlies got back to Grit ’N’ Grind.

A lot of people either wrote off or simply forgot about the Grizzlies after a dismal 2017-18 campaign in which they finished with 22 wins and the second-worst record in the league. But the case for believing in Memphis this season was relatively straightforward: This group, finally healthy with the return of Mike Conley and a more motivated Marc Gasol, had its best players back and added considerable two-way talent over the summer through a handful of deals.

Rookie Jaren Jackson Jr. looks like a potential star at times and is already the real deal defensively. The Memphis defense can be overly aggressive at times in helping from the weak side, which leaves corner shooters open more often than most teams. But the Grizzlies’ D is a top-5 unit, and it gets downright nasty when Jackson and Gasol play together, surrendering just 96.8 points per 100 possessions in 287 minutes. (Oklahoma City, which leads the NBA in defensive efficiency, allows 102.6 points per 100 possessions.)

In case you need a sign of how smart the Grizzlies’ offseason pickups were, consider this: The team’s three most-efficient rotation players to this point — Omri Casspi, Shelvin Mack and Jackson — were all acquisitions from this summer. Gasol is fourth on that list, but right behind him is Garrett Temple, for whom the Grizzlies traded.

So don’t be too surprised if Memphis continues to hang around in the playoff race. There were indications all along that the Grizzlies would find themselves in the midst of this conversation.

Surprising: Derrick Rose’s offense came back to life.

Rose’s first career 50-point game earlier this year got considerable attention, but that game was no fluke: This whole season in Minnesota has been a consistent one for the former MVP. From an efficiency standpoint, he’s actually never played this well before.

He’s shooting a career-best 49.8 percent from the field, and his 60 percent mark from a true shooting standpoint is 5 points better than he’s had in any other season. Rose used to be among the NBA’s worst 3-point shooters — enough of a liability that he essentially stopped taking triples altogether in New York — but he’s been good from that range, too. The 30-year-old, who’s long been a surprisingly good midrange shooter despite having the flattest shot in the game, is better than 48 percent from 3-point distance on almost four attempts per game to this point. His hot start even has him ranking as one of the NBA’s 15 most efficient offensive players, according to ESPN’s Real Plus-Minus metric.

It’s still early, but this shooting display — even if his numbers fall off some — figures to lengthen his career, a meaningful development based on how things were going 10 months ago. We knew his otherworldly athleticism wouldn’t be the same after all his injuries, but a steady jumper has changed his outlook.

Not surprising: The Rockets-Melo marriage failed.

We, like many others, fully recognized the potential pitfalls with Houston’s Carmelo Anthony acquisition this summer. He seemed a less-than-ideal fit, particularly as a sort of replacement for the switchy wing defenders the Rockets lost in Trevor Ariza and Luc Mbah a Moute. So it’s not necessarily shocking that the experiment didn’t work.

But never did we imagine that the team would pull the plug as quickly as it did. Houston cut bait on the fallen star just 10 games in — even though other clear problems seemed to exist (like the lack of depth behind Clint Capela, or Eric Gordon shooting far worse than he ever has). Still, it’s somewhat difficult to knock the haste with which the Rockets made the decision: They couldn’t afford to fall too far behind in the loaded Western Conference, where the playoff race figures to be a bloodbath, and they began playing far better after making the pragmatic choice to hold Melo out of the rotation. But even after winning five straight at one point earlier in the month, Houston now finds itself mired in a four-game skid, meaning that there’s more for this club to figure out.

Surprising: California’s other NBA teams have been legitimately good.

It was totally fair to wonder whether Los Angeles might be a factor in the Western Conference playoffs this season, but who would’ve thought that the Clippers would be the team making that kind of noise at this point in the year? (In fairness, LeBron James and the Lakers have played well lately, too, and may very well find themselves in the same conversation as we move forward.)

A number of things illustrate how and why Doc Rivers’s team finds itself atop the West for the time being. The guard rotation of Patrick Beverley, Avery Bradley and Shai Gilgeous-Alexander has done a fantastic job of defending; the Clippers have held opposing starting guards to 40.9 percent shooting, the NBA’s fourth-lowest figure through Tuesday’s games, per the ESPN Stats & Information Group. Danilo Gallinari, who hasn’t played more than 65 games in a campaign in six seasons, has missed only one game thus far and is shooting better than he ever has from outside.

But above all else, the Clips have thrived because Tobias Harris — tied with Giannis Antetokounmpo for the league’s best effective field-goal percentage among wing players with at least 300 shot attempts — has quietly pieced together the offensive profile of a superstar this season. Between the huge leap he’s made and the gains of Victor Oladipo, the Orlando Magic front office has to be beside itself after trading away both players.

And while Golden State has been Golden State so far, another Northern California team has been making a move. The Kings own a 10-10 mark and have been one of the more entertaining clubs so far. Just about everything begins and ends with their blistering pace. It seems possible that their ability to maintain that 106-possessions-per-48-minutes tempo for entire games may work to their advantage in the clutch, when Sacramento’s opponents simply don’t have anything left.

Sacramento ranks 22nd in defensive efficiency in the first quarter, 25th in the second period and tied for 16th in the third, yet it sits sixth in fourth-quarter defense, right behind the defending champ Warriors. And get this: Despite the pace at which they play, the De’Aaron Fox-led Kings have yet to commit a clutch-time turnover this season — they’re the only team that can still make such a claim this late in the season. It’s part of the reason they are 8-3 — best in the Western Conference — in contests separated by 5 points or fewer with five minutes or less remaining, per NBA.com.

Not bad for the NBA’s third-youngest team, one whose young players all seem to have taken a step forward this season.

Check out our latest NBA predictions.