After a pretty ugly start to the season, at least relative to expectations, the Celtics have won eight of their last nine games entering action on Tuesday. And they're not just winning -- they're destroying teams by an average of 18.5 points per 100 possessions over that stretch. That's double the second-best net rating in the league over the same stretch (San Antonio plus-9.3). Boston's offense, which had been a bottom-10 unit for most of the season, vaulted to No. 1 over this recent stretch with a world-beating 120.6 rating. It's like night and day. 

Any time a team turns things around to this degree, there are multiple factors in play. Brad Stevens inserting Marcus Smart into the starting lineup is certainly one. Marcus Morris has been superb as a starter as well. Most notably, Kyrie Irving is making all kinds of plays. Over the last nine games, Irving is averaging 24.9 points on just under 50-percent shooting, including 46.6 percent from three, and Boston is outscoring opponents by almost 18 points per game during his minutes. 

In watching the film, one thing that jumps out is the great pace Irving is playing within the half court. People tend to talk about pace in terms of up-tempo transition offense and fast breaks, but pace is equally important, if not more, in the half court. "The teams that are always cutting hard and playing downhill, catch and attack, putting that constant pressure on the defense, those are the teams that are the hardest to guard," Pelicans assistant coach Darren Erman told CBS Sports.

In the play below, watch how Irving comes to the ball to receive the pass, almost like a receiver coming back to the quarterback, effectively setting his man up for a pick and roll before he even receives the ball. When he catches the pass, he's already headed downhill with a step on his defender, and the roller is already in the lane. That forces the defense to collapse, and tic-tac-toe, you create a wide-open three on just two passes. 

Watch here as Terry Rozier fakes a dribble handoff to Kyrie before passing to Jaylen Brown, who immediately attacks. The drive is cut off, but Brown's downhill aggression has forced the defense to start gravitating, and the second Kyrie sees an opening, he cuts hard to the rim. 

Don't worry about the miss there. It's the pace that matters, two players attacking --  Brown with the ball, Kyrie without it. The only guys standing still are the floor spacers, which provides Kyrie with the runway to the rim. That is downhill basketball. That kind of urgency in the half-court is contagious. Pretty soon everyone is playing fast and decisive. 

Watch this next possession. Even on a make, Kyrie immediately pushes the ball ahead to Rozier, who goes straight into a pick and roll. From that point forward, the ball is popping and everyone is moving until Kyrie finally cuts to daylight for a layup. 

That is gorgeous offense, and it speaks to the most important thing that playing with this kind of pace affords you: Options. Pretty simply, the faster you get into your offense, and the faster you then run through your actions, the more actions you can go through before the shot clock starts dwindling down. Rozier's initial pick-and-roll is thwarted, so he kicks it out. He gets it right back. He runs another pick-and-roll. Daniel Theis pops this time, and has an open jumper. But Irving has a layup. Pass up the good shot for a great shot. Boom-boom-boom. Bucket. 

"It's hard to guard NBA players for that long," Erman says. "If you're playing with pace for 15-20 seconds, cutting and moving and attacking downhill, something will almost always open up."

Again, the Celtics have been doing a lot of things well as they've gotten some real momentum going for the first time this season, and they'll try to keep that alive against the Suns on Wednesday (7:30 p.m. ET -- Watch on FuboTV with the NBA League Pass extension). This is just one element. But it's a big one. When Boston is struggling offensively, it gets stagnant. Kyrie can be guilty of that himself. But he is setting the tone of late. Whether he's coming for a dribble hand-off for a pull-up three, running pick-and-roll or cutting off the ball, he is clearly making a concerted effort to be in constant attack mode. And it's trickling down to the rest of a Boston offense that is finally starting to look as dangerous on the court as it does on paper. 

Is it safe to trust the Raptors ... again?

Last year, I fought buying into the Raptors as true contenders for as long as I could. Then, like most everyone else, I caved. Said they were a legit Finals threat. I cited the defense. The bench. I talked myself Into them being a different team than in years past. Lo and behold, I had it right the first time. Toronto was a pretender. Swept at the hands of LeBron James -- and I guess, technically, the rest of the Cavs -- in humiliating fashion. 

Now here we are again, jumping on the Toronto bandwagon. 

The rationale sounds very similar to last season -- the defense, the depth, the versatility. Last year, OG Anunoby was every smarter-than-you blogger's favorite player. This year it's Pascal Siakam. Once again we're talking about Toronto's different offensive system, this time implemented by new coach Nick Nurse. Earlier this season, a league scout told me Toronto is the "clear favorite" to win the East for all these reasons. Plus ...

"Kawhi [Leonard] gives them that star you need in the playoffs," the scout said. 

Oh yeah. That guy. Turns out, the only reason we really, truly believe all this good stuff we're saying about the Raptors being a legit title contender -- like, for real this time -- is the fact that they have Kawhi Leonard. If this team really is different, he's the difference. That sounds obvious, but it's worth pointing out. We get so caught up these days in breaking down the nuances of teams' offenses and defenses -- advanced stats this, lineup versatility that -- that we sometimes forget basketball, more than any other sport, is mostly about players making plays. 

Yeah, schemes play a role. A good or bad coaching decision, whether it be a lineup shuffle, an out-of-bounds play or whatever can swing a game. No teams win at the highest level without really good supporting players and disciplined execution on both ends of the floor. Kyle Lowry has been terrific this season, but he's been terrific before. Hasn't gotten them anywhere when it counts most. In the end, to be a real threat at the highest level, you have to have great players making consistently great plays. 

This is especially true in the playoffs when scouting becomes so precise that nobody is fooling anyone by Game 3 of a series. That pin-down screen that got you an open look in January gets sniffed out and switched in May and June. Systems can grind to a halt, at which point somebody simply has to beat his man and make a play for himself or somebody else. Somebody has to pull up for a three with a hand in his face and drill it. Somebody has to dig in on defense, when everyone in the world knows who's going to take the shot, and lock up the best player on the other team in the biggest moments. 

In the playoffs, you have to have a dude

Look at last season: Toronto was, collectively, a far superior team to the Cavs. They had a better defense. Better role players. They had more depth. More play-makers. But the Cavs had the best player in the series. So they won. Easily. As I continued to talk with this aforementioned scout, he put it in a succinct, and I think a very smart, way: The gap between the best players in the league, and the best player on the Raptors, has shrunk considerably. 

No disrespect to DeMar DeRozan, but in a seven-game series, he couldn't keep up with the LeBron's or the Kevin Durant's or the Steph Curry's or the Kyrie Irving's. Kawhi Leonard can. That doesn't mean he's better than those guys (even though he certainly can be on any given night), but you don't necessarily have to have the best player on the floor to win in the playoffs. You just can't be miles behind in that department. 

A good example of this: Three weeks ago, Kevin Durant had 51 points, 11 rebounds and six assists against the Raptors, and Toronto still beat the Warriors. Its true, neither Curry nor Draymond Green played, but the fact remains, the Warriors had the best player on the floor that night. They scored 128 points. They weren't going to score much more than that no matter who was out there. Durant was the guy that night. He was the LeBron who would've single-handedly destroyed Raptors teams of old. 

But not this time. This time, Toronto was able to counter with Kawhi, who posted 37 points, eight rebounds, a steal and a block. It wasn't the night Durant had, but it was enough for all those other assets Toronto possesses -- the bench, the multiple playmakers, Kyle Lowry -- to make up the difference. Come playoff time, as simple as it sounds, Toronto will be counting on a similar formula to prove that, this time around, it really is safe to trust them as a title contender.