Robb: Just how good are these Celtics?

The 6-2 Celtics went to sleep Wednesday night in a tie on the top of the Eastern Conference and the NBA after putting the finishing touches on their third blowout win over the past six games, a 113-86 victory over the hapless Sacramento Kings.

The six consecutive wins for Boston is the best stretch for any team in the NBA this year and the streak that started as a feel-good story following the season-ending injury to Gordon Hayward has become a bit more than that in recent weeks. Fans, analysts, everyone is starting to wonder a little bit about this Hayward-less squad and what exactly Brad Stevens has molded together despite losing arguably the best all-around player on his roster five minutes into the season.

Are the Celtics for real? It’s hard to give an accurate and realistic assessment so early when some of these wins are coming against the likes of the Knicks and Kings. The schedule hasn't been rough overall. They have faced teams with injuries. A lot of variables have come into play. Despite all of that, some words from Spurs head coach Gregg Popovich in Boston on Monday night stuck out to me when considering the level of play this group is sustaining.

“We actually played better even though we got our ass kicked,” Popovich said after his Spurs suffered a 108-94 defeat. “I saw some things that I liked, but we got a lot of stuff to go over with a lot of new guys. It's coming slowly, but I think it's going in the right direction. I thought the Celtics movement was great, I thought they executed really well offensively and they are playing with some edge and some physicality and I think they look wonderful.”

San Antonio was without Kawhi Leonard and Tony Parker in the loss, but Popovich praising his team’s effort in a blowout speaks volumes about how legitimate this Celtics team is right now.

Defensively, this group is showing literally no weaknesses early on. They rank in the top-12 in all defensive four factors categories (field-goal defense, free-throw rate, defensive rebounding rate, turnover rate). The defensive rebounding that was a weakness for the past several seasons is now a top-5 group in the NBA. That production and overall balance has them atop of the NBA in defensive rating (allowing 95.1 points per 100 possessions), with strong work from both the starting unit and the bench.

“It starts from the top with Brad,” Jaylen Brown noted after the Celtics allowed a season-low 86 points. “That is his emphasis, defense, so we got to try and come out and stay consistent on that side of the ball every single night which is tough to do. I’m pleased to see where we are at defensively and I think we can be a whole lot better. I think we have a good group of guys who work their tails off to get better and I think we are going to continue to go up from here.”

Offensively, the Celtics started the year below-average, but they are slowly creeping up in the offensive rankings as well. Boston now ranks 13th in the NBA in offensive rating (105 points per 100 possessions) after starting the winning streak in the bottom third of the league on offense. That's an encouraging start since, on the whole, they haven’t shot the ball particularly well yet. They rank just 20th in field goal percentage (44 percent) and 13th in 3-point percentage (36.2 percent) through eight games. There is plenty of room for growth as the new pieces get better acclimated and more reliable scorers (like Marcus Morris) return to the fold.

“It’s going to continue to get better,” Kyrie Irving said after the win Wednesday. “Just continue to trust the pass. Understand that our system works. Brad does a great job of putting out a great game plan and it’s just our job to execute it. And he’s one of the best in the league at it, if not the best of just running plays and just drawing up plays for us to be successful, and for our individual talents to be at our all-time high.”

The biggest thing that sticks out after pouring through the individual numbers for this group is that there isn’t a lot this team is doing right now that’s unsustainable for the long haul. Irving’s only averaging 21.8 ppg and shooting a rather pedestrian 44.5 percent from the field and 35 percent from 3-point range. Youngsters like Jayson Tatum (11-of-22) and Jaylen Brown (16-of-39) have come out red-hot from downtown, but those numbers have been balanced out with subpar overall shooting from the likes of Marcus Smart (31 percent), Terry Rozier (38 percent) and Semi Ojeleye (33 percent).

Can Brown average 16 points per game? Can Tatum post 14-and-6 on a nightly basis as a rookie? It’s hard to find any evidence that those types of numbers are a major reach at this point for either of those guys. Supporting players like Daniel Theis, Aron Baynes, Terry Rozier and Marcus Smart are excelling in their roles, to the point that the bench unit is actually building or adding to leads in extended minutes together.

“I think everybody’s settling in, everybody’s in a good rhythm right now and offensively I think we can continue to play well,” Brown said. “We have a lot of young guys, and I think we’re playing a lot older than our age says.”

A better measuring stick will be coming over the weekend during a three-game road swing that includes stops in Oklahoma City and Orlando against a red-hot 6-2 Magic squad. Those contests will give us a better sense of where this group stands on the whole. However, it’s hard to ignore a net rating of 9.9 (fourth in the league) and the consistency this squad is already showing on a nightly basis after getting over the shellshock of Hayward's injury.

A couple weeks ago, a 50-win team seemed like a bit of a pipe dream without Hayward in the fold. With every passing game, that type of season and a deep postseason run is not only seemingly within reach, it could become a realistic expectation.