The first month of the NBA season is all about establishing storylines. And among the typical annual storylines -- the Golden State Warriors' dominance, LeBron James' greatness, the ascendance to MVP status for young superstars like Anthony Davis and Giannis Antetokounmpo -- there are always a bunch of surprises.

Last year the biggest surprises were Victor Oladipo and Donovan Mitchell.

This year? There have been plenty of surprises. Such as: The Denver Nuggets have the fourth-best defensive rating in the NBA -- after ranking 23rd last season. The Bucks shoot more three-pointers than all but one NBA team; last season, 24 teams shot more threes than Milwaukee. Names like Alfonzo McKinnie, Serge Ibaka, Domantas Sabonis and JaVale McGee, weren't exactly on the tip of anyone's tongue at the beginning of the season. Yet here we are, one month into a season that's been full of surprises.

Here are this week's Power Rankings: 

Biggest Movers
4 76ers
5 Pacers
1 Warriors The Warriors have the most elite talent in the NBA. So how come they're always able to find someone from the scrap heap and turn them into a valuable role player? As recently as 2016, Alfonzo McKinnie was playing in Luxembourg and Mexico before paying $175 for a tryout with the Chicago Bulls' minor-league team. Days before opening night, the Warriors agreed to a two-year contract with McKinnie -- and the wing has become an invaluable part of their rotation. Only two bench players for the Warriors have logged more minutes than McKinnie this season. He's averaging 6.6 points and 4.0 rebounds while shooting 48.1 percent from three. --
2 Raptors The renaissance and reinvention of Serge Ibaka, who has primarily been playing the five, has been one of the biggest reasons the Raptors feel like the team most likely to topple the Warriors' dominance. Ibaka is second on the Raptors in scoring, averaging 17.2 points per game, which would be a career high. Ibaka's done his damage closest to the rim, leaving three-point shooting to teammates. He's shooting fewer threes than any season since 2013-14. --
3 Bucks Mike Budenholzer's pivot to three-point shooting has been dramatic, and the biggest reason why the Bucks look to be a top-tier team in the East. No team has made more threes than the Bucks; last season they ranked 27th in made three-pointers. Brook Lopez rained eight threes down on Sunday night to lead the Bucks past the Nuggets. Only two players have made more three-pointers this season than Khris Middleton (Steph Curry and Kemba Walker). Last season Middleton took 5.5 mid-range shots per game, eighth-highest in the NBA. This season he's only attempting 1.9 mid-range shots per game. --
4 Nuggets The Nuggets have the NBA's best defense. I repeat: The Denver Nuggets, who ranked 23rd in defensive rating last season, rank No. 4 in defensive rating this season. This felt like an anomaly for the first couple weeks of the season. Now it feels like this team has turned a corner. --
5 Trail Blazers Zach Collins' emergence during his sophomore season has been a pleasant surprise for the Blazers. Head coach Terry Stotts has been playing Collins 21.5 minutes per game, up from 15.8 minutes per game last season. 2
6 76ers Ben Simmons looks like virtually the same player as during his rookie season, which may be a problem for the Sixers, since the biggest jump often comes during that first offseason. But whatever. The Sixers now have Jimmy Butler, and are one of only two teams in the NBA to have three top-20 players. This defense is going to be one of the best in the NBA. Thus the jump in these Power Rankings. 4
7 Celtics The Celtics can't make shots. They rank 24th in offensive rating (they were 18th last season) and 23rd in true shooting percentage (they were 14th last year). Jaylen Brown and Al Horford are both shooting career lows from three, and Gordon Hayward's 31.8 percent isn't far off. 2
8 Jazz Rudy Gobert has taken advantage of the freedom of movement rules and become a more potent offensive force. Fellow big men can't just push Gobert around anymore, and Gobert is averaging a career-high 16.4 points per game and leading the NBA in shooting percentage. He has become one of the top lob threats in the NBA. 1
9 Spurs The Spurs are zigging when the rest of the NBA is zagging. As the rest of the NBA pushes even further with the three-point revolution, Gregg Popovich's team is shooting way more mid-range shots than the rest of the league. Led by LaMarcus Aldridge and DeMar DeRozan, the Spurs take 28 mid-range jumpers per game, nearly six more attempts than the next team (the Warriors). 3
10 Rockets How can this defense really be that bad? One stat that was making the rounds over the weekend could explain it: The Rockets had a net rating of -9.0 with Carmelo Anthony on the court and +1.8 with him on the bench. That's 11 points per 100 possessions worse with him on the floor, the worst net rating in the NBA of any player to have played more than 100 minutes. (h/t @HPBasketball). CBS Sports' projections have the Rockets being two wins better this season without Melo -- the definition of addition by subtraction. 2
11 Pacers Domantas Sabonis has been a force for the Pacers so far -- better than fellow big man Myles Turner, who recently agreed to a four-year, $72 million extension. Sabonis ranks third in the NBA in field goal percentage and second on the Pacers in scoring. 5
12 Thunder The Thunder are, after a rough first week, exactly what we thought they would be: A team that struggles to make shots but makes up for it on defense. The defense ought to get even better once Andre Roberson returns. But it's surprising just how bad the shooting has been. Three rotation guards are shooting 11 percent or less from three: Russell Westbrook, Raymond Felton and Hamidou Diallo. And Dennis Schroder is shooting only 27.9 percent from three. 1
13 Clippers The Clippers are second in the NBA in three-point percentage and are first in bench scoring. A solid team all the way through. 1
14 Pelicans When he's been healthy, Elfrid Payton has been exactly what the Pelicans needed as a Rajon Rondo-type backup point guard. But he's missed seven straight with a bum ankle. They need him, because point guard depth is not this team's strength. 3
15 Hornets Michael Kidd-Gilchrist getting minutes at the 5 in a Draymond Green-like role has revitalized his career and given the Hornets some serious switchability. James Borrego seems like a smart hire. --
16 Lakers JaVale McGee has been a two-way force for the Lakers. He's third in the NBA in blocks, and averaging more minutes than any season since 2010-11, his third year in the NBA. Imagine how much worse the Lakers' middling-at-best defense would be if it weren't for McGee. He's been effective on offense as well for a team that takes far more shots in the restricted area than anyone else. --
17 Grizzlies Grit and Grind is back, and Marc Gasol is too. The Grizzlies are bucking all the trends of the 2018-19 NBA season, playing stellar defense (fifth in net rating) and a slow pace (last in the NBA) -- yet are sitting pretty at 7-4. And at age 33, Gasol isn't finished. He's shooting 46.2 percent from three and anchoring a near-elite defense. 1
18 Kings The Kings might be the biggest surprise in the NBA so far, and it's because of two youngsters who have made a major leap this season: Willie Cauley-Stein and De'Aaron Fox. Cauley-Stein has been a big lob target and a force in the restricted area; only seven players have attempted more shots in the restricted area than Cauley-Stein, who is averaging a career-high 16.8 points per game. And the speedy Fox has become everything the Kings would have hoped in his sophomore season. Most surprisingly, he's shooting 41 percent from three-point range, which had been his Achilles heel. 1
19 Pistons Blake Griffin looks like an All-Star again, though he's doing it in a completely different way than he had in the past. No longer quite the high flyer he once was, Griffin has evolved into a complete basketball player by virtue of dead-eye three-point shooting. He's shooting a career-high 39.1 percent on a career-high 5.8 three-point attempts per game. 1
20 Heat Josh Richardson's usage is not as high as it was earlier in the season, but he's still the Heat's highest-usage player. At a 23.9 percent usage rate, Richardson is in the neighborhood of stars like Nikola Jokic, Karl-Anthony Towns and Khris Middleton. 1
21 Timberwolves In what has been an absolute nightmare season for the Timberwolves, two surprising bright spots have been the resurrection of Derrick Rose (averaging 18.8 points per game) and the effective play of rookie Josh Okogie (who brings incredible energy in 26.4 minutes per game). Everything changed this weekend with the trade of Butler to the Phildelphia 76ers. The addition of Robert Covington and Dario Saric gives the Timberwolves -- on paper at least -- an intriguing, spread-the-floor lineup around Karl-Anthony Towns. 4
22 Nets Caris LeVert might be the closest thing this team has to a star, but the Nets' most valuable player so far this season might be Joe Harris. He's averaging 29.2 minutes per game, has the team's best net rating and leading the NBA in three-point percentage (57.8 percent). --
23 Magic Nikola Vucevic isn't this team's future, but he's been a surprising bright spot for this team's surprising present. Vucevic is averaging 17.8 rebounds and 10.7 rebounds and posting a 24.6 player efficiency rating -- all team highs. 4
24 Wizards There may be no bigger gulf in the NBA between a team's talent and a team's record than the Wizards. Otto Porter's regression this season has been stark. That four-year, $106 million contract looks like one more albatross contract for the Wizards. --
25 Mavericks DeAndre Jordan's defense is a shadow of what it once was. He still swats the occasional shot into the stands with force, but you get the sense he's just not trying as hard as he can. That's a big reason why the Mavericks have only the 24th-ranked defense in the NBA. --
26 Bulls Zach LaVine is getting star treatment in Chicago, and he's reacting well to it. LaVine ranks fourth in the NBA with 27.2 points per game, and fourth in the NBA in usage percentage. Plenty of people derided the Bulls for matching LaVine's offer sheet in the offseason. His four-year $78 million contract doesn't look nearly as bad today as it once did. --
27 Knicks Tim Hardaway has made more threes so far this season than all but four NBA players. He ranks ninth in the NBA in usage percentage, between Steph Curry and Kawhi Leonard. 1
28 Hawks The Hawks may not be good. But they are fast, and they are fun. They're the fastest-paced team in the NBA, and shoot more threes than all but three teams. It's going to be fun to see how this team develops in Trae Young's image. 5
29 Suns Is Josh Jackson really this bad? The fourth pick in the 2017 draft has regressed from his middling rookie year. He's second in the NBA in turnover percentage. He's playing seven fewer minutes per game than a year ago. He still can't shoot. I remember hearing the odd scout or pundit saying that Jackson could turn out to be the best player in that draft. That feels silly now. --
30 Cavaliers Everyone outside of Dan Gilbert knew the Cavs were going to be bad after LeBron left. But did anyone imagine they'd be this bad? --