The NBA is becoming a positionless league. Coaches are more comfortable playing nontraditional lineups, cross-switching defensive assignments, and sliding players between positions. However, there are still five spots in a lineup, and what spot a player occupies still matters. Every five-man group needs someone to perform a few basic roles so everything one guy does (or doesn’t do) impacts his four teammates. That’s why who plays where is more important than ever. More positional flexibility means more diversity in the types of players at each spot. This series will take a look at how each position is changing, through the lens of three starters, each with a different skill set.

No position has changed more over the last generation than power forward.

When guys like Enes Kanter and Greg Monroe were drafted at the start of the decade, the idea was to play them at the 4 and pair them with another more defensive-minded big man in a Twin Towers lineup. These days, Kanter and Monroe anchor second units as backup 5s, which makes their inability to shoot or slide their feet on the perimeter less of an issue. While they can still be dominant scorers in the right situation, their main strengths don’t fit into the modern spread pick-and-roll offense, where big men are expected to either spread the floor from behind the 3-point line or catch lobs at the rim. More importantly, those offenses are built to expose slow-footed behemoths who want to stay in the paint. Monroe and Kanter had to be taken out of the starting lineup for their own safety. Asking them to guard a player like James Harden in space is just cruel.

Now that everyone is running pick-and-rolls and shooting 3s, the landscape at the 4 spot has changed. If power forwards are spending most of the game spotting up 25-plus feet from the basket, smaller, more perimeter-oriented athletes who would never be able to survive in the post against old-school Goliaths like Zach Randolph become more valuable. Conversely, the worm has turned for stretch 4s like Ersan Ilyasova, who has played for six teams in the past three seasons. The Turkish forward was a mismatch nightmare for traditional big men because he could hold his own in the paint and take slower defenders out on the perimeter. However, opposing teams can go small against him knowing he can’t punish them in the post, and then attack him in the pick-and-roll on defense. The stretch 4 has gone from the cutting edge to obsolete in a couple of years. The revolution is starting to eat its own.

Teams are abandoning the power forward position entirely and sliding small forwards from the 3 to the 4. Shawn Marion was one of the first combo forwards to make the transition back in 2004, and now everyone is doing it, with former lottery picks like Marvin Williams and Al-Farouq Aminu, once considered busts, reinventing themselves as small-ball power forwards. On the other hand, established veteran 4s like Boris Diaw, Luis Scola, David Lee, and Josh Smith have fallen out of the league, and once-promising youngsters like Donatas Motiejunas, Terrence Jones, and Thomas Robinson can’t find NBA jobs. Some 4s have been able to transition to the 5, but the league isn’t exactly running low on centers either. It’s kill or be killed at power forward, where the game has changed and everyone is fighting for a job.

Harrison Barnes

There wasn’t much optimism surrounding Barnes when he signed with the Mavs last offseason. He was coming off a terrible performance in the 2016 NBA Finals, where the Cavs shattered his confidence by leaving him wide open, and he was no better than Plan C or D in Dallas, who had once again struck out chasing the top free agents on the market. How would a player who struggled in a smaller role on one of the best offenses in the league fare in a bigger role on an aging team with an unsettled point guard situation and whose best player was 38 years old? As it turns out, pretty well. Jumping from complementary player to featured player is incredibly difficult, but Barnes was able to do it without losing much efficiency:

Barnes’s Usage and Efficiency Season Usage Rate True Shooting Percentage Season Usage Rate True Shooting Percentage 2015-16 15.9 0.559 2016-17 25.3 0.541

The difference was a position change. The extra time spent at power forward due to an early-season injury to Dirk Nowitzki was the best thing to happen to Barnes, who became a mismatch when he moved from the 3 to the 4. At 6-foot-8 and 225 pounds with a 6-foot-11 wingspan, Barnes has average size for a 3 and is slightly undersized for a 4, but he’s an elite athlete who is built like a rock and can match up with much bigger players. His greatest moment in Golden State came in the 2015 playoffs, when he slid up a position and shut down Z-Bo when the Grizzlies had a 2–1 lead in the second round. It’s not easy to move Barnes after he establishes position: According to the tracking numbers at Synergy Sports, he was in the 68th percentile as a post defender in 137 possessions last season. Look at how he’s able to muscle up Blake Griffin in this sequence:

On the other side of the ball, Barnes had much more success attacking bigger and slower defenders than he did against guys his own size. While he’s a skilled player who can shoot off the dribble, he doesn’t have a particularly quick first step, and he has difficulty creating separation against the best defenders at the 3. The numbers bear out the difference. Barnes went from scoring 0.815 points per possession on 65 isolations two years ago in Golden State to 0.932 points per possession on 369 in Dallas, where he was the seventh-leading isolation scorer in the NBA. Watch how smoothly he takes Thon Maker off the dribble:

Barnes embraced the midrange game last season, attempting 338 shots in the dreaded “long 2” range from 16 feet out to just within the arc. He wasn’t quite as efficient in that area of the floor as Dirk, but he made just enough shots (39.9 percent) to make Rick Carlisle feel comfortable giving him the green light. The problem was settling for those shots made it harder to get fouled (3.6 attempts per game) or distribute (1.5 assists). Defenses didn’t overload to stop him, and he’s not an intuitive enough passer to find angles out of one-on-one coverages. There’s a ceiling to how good a team can be with Barnes as the primary option, and it will be interesting to see how he fares next to rookie point guard Dennis Smith Jr., who will likely get a much bigger role than the rotating cast of characters the Mavs rolled out at the position last season.

The fit between Dirk and Barnes is tricky as well. When Dirk returned to the lineup in the middle of the season, the Mavs downsized even further by playing Nowitzki as a small-ball 5, a move which stretched defenses past the breaking point but left Dallas dangerously exposed at the rim and on the glass. They were the worst rebounding team in the NBA, in part because their starting 4 averaged five rebounds per game. A full season of Nerlens Noel should help, but that still leaves three frontcourt players for two spots at the end of the game.

Defenses will adjust to Barnes more this season, likely using their 3 to guard him more often while hiding their 4 on Wesley Matthews, who isn’t as equipped to take bigger defenders off the dribble. Barnes is better when he’s the smaller player in a matchup, which is why the Mavs changed his position in the first place. However, the best players in the NBA can dictate matchups both ways, and Barnes needs to show he can be a dominant scorer against players his own size, too. He was ahead of the curve when he moved from the 3 to the 4, but as more of his peers join him, a lot of his advantages at his new position will go away.

Frank Kaminsky

Kaminsky will probably be forever known in Charlotte as the guy the Hornets refused to trade for four first-round picks, when the Celtics tried furiously to jump up to take Justise Winslow in the 2015 draft. Frank the Tank was coming off a storied four-year career at Wisconsin, where he developed into one of the best offensive players in the country, a sweet-shooting 7-footer who could score off the dribble and in the post, making him almost unguardable at the college level. Stardom has not come as easy in the NBA, where Kaminsky has been a solid but unspectacular player, averaging 11.7 points on 39.9 percent shooting, 4.5 rebounds, and 2.2 assists per game last season.

Kaminsky has slid between both frontcourt positions in Charlotte, spending time as a supersize 4 next to Cody Zeller and a small-ball 5 next to Marvin Williams. He’s versatile enough to handle either spot, at least offensively. Poor play from Roy Hibbert, Miles Plumlee, and Spencer Hawes, as well as an injury to Zeller, allowed him to play more center. However, Charlotte’s trade for Dwight Howard earlier this summer means Kaminsky will play almost exclusively at power forward when everyone is healthy. A guy moving from the 5 to the 4 is pushing against the tide, but there are so many players who can play only as centers in today’s game. Most teams in the NBA have a numbers crunch up front, and in order to get playing time, 7-footers like Kaminsky have to prove they can be more helpful at the 4 than converted 3s.

The key for Kaminsky is improving his shooting. He was a 41.6 percent shooter from 3 in his last season at Wisconsin, but he’s a career 33.1 percent 3-point shooter (on 3.6 attempts per game) in the NBA. While those are decent numbers for a stretch 5, a 4 playing with a nonshooting big man like Howard or Zeller has to be better, especially in Charlotte, which runs as much pick-and-roll as any team in the league. Williams, the player Kaminsky is now backing up, takes more than half of his field goal attempts from 3. The Hornets need floor spacing from their power forwards because they don’t get any from Michael Kidd-Gilchrist, who attempted only nine 3s all season, or new backup point guard Michael Carter-Williams.

Kaminsky has two things going for him: his feel for the game and how fluid he is with the ball. He’s not your prototypical stretch 4 who can run only pick-and-pops; he’s comfortable initiating offense and slicing passes through the lane. Kaminsky averaged 2.2 assists and one turnover per game last season, and he could be an intriguing cog in a more traditional offense like the triangle, which puts big men in the high post and asks them to make plays. If he’s operating in tighter spaces in bigger lineups next season, the ability to make plays in traffic will be crucial for him. Watch him expertly run the pick-and-roll with Miles Plumlee from the top of the key in this sequence:

Conversely, Kaminsky isn’t as effective when he’s operating as more of a traditional big. He was only in the 39th percentile of players in the NBA on post plays, scoring 0.841 points per possessions on 113 attempts last season. At 7 feet and 240 pounds, Kaminsky has a fairly narrow build that prevents him from establishing deep position against smaller but thicker players, while his substandard wingspan (6-foot-11) makes it difficult for him to score over the top of players in the post. In this sequence, Michael Beasley pushes Kaminsky out of the paint and forces him into taking an almost-impossible leaner:

Offense is crucial for Kaminsky because a big man without long arms, quick feet, or a strong base is never going to be much of a factor defensively. He was in the 37th percentile of NBA players in defending isolations last season, and in the 35th percentile in defending roll men. Steve Clifford prefers to play a more conservative defensive scheme that asks his big men to drop back in the pick-and-roll and defend the paint, but even when he’s giving up space, Kaminsky still struggles to get over fast enough to protect the rim. Isaiah Thomas turns the corner against him like he’s not even there in this sequence:

Kaminsky’s inability to anchor a defense means his days as a small-ball 5 were probably numbered, even if Charlotte hadn’t beefed up their center rotation. The Hornets bled points when Kaminsky was the sole big man on the floor: Their most frequently used lineups with him at the 5 last season had defensive ratings of 107.8, 109.9, and 116.7 — all worse than the 106.1 points per 100 possessions the team gave up as a whole. For as much as he dictated matchups in college, he’s a modern-day tweener in the NBA: not good enough defensively to be a 5, or productive enough offensively to be a 4. He was an elite scorer in the NCAA, and he has to get back to that caliber to be effective at the next level.

Julius Randle

Randle is another guy who has not been able to translate his college stardom to the NBA, and he’s coming up to a crossroads in his career. Because the Lakers are more concerned with preserving their cap space for next summer, Randle is stuck in limbo, unlikely to get the kind of extension lottery talents often receive, since the Lakers are more concerned with preserving their cap space for next summer. This is a make-or-break year for him: He’s playing for a new contract, and there will be serious competition for minutes at the 4 with Larry Nance Jr. and rookie Kyle Kuzma.

At 6-foot-9 and 250 pounds, Randle still has the same combination of brawn, quickness, and skill that had him pegged as a future NBA star when he was in high school. There just aren’t many guys his size who can move as well as he does and who are as capable of making plays. But he comes with significant limitations. He’s neither long (7-foot wingspan) nor particularly explosive in the air, so he’s not effective playing bully ball in the paint: He was only in the 15th percentile league-wide of post scorers. Randle is at his best operating in space and whipping passes on the move, and it’s easy to fall in love when watching his highlight reel:

All those flashy plays, though, haven’t helped the Lakers much. Los Angeles has been one of the worst teams in the NBA since Randle came into the league, and he is a big reason. The Lakers had a net rating of minus-10.2 when he was on the floor last season, the worst of any of their rotation players, and a net rating of minus-3.5 when he was off, the best mark for anyone on their roster. Randle’s unique skill set is the worst of both worlds: It’s difficult to build a lineup around a 4 with his strengths, and it’s almost impossible to hide his weaknesses. He can’t shoot to save his life, and he gets roasted on defense. Nance is a better defender and Kuzma is a better shooter: While they may not have Randle’s upside, they don’t have his downsides either.

There was hope Randle could develop a jumper in the NBA, but it hasn’t happened yet. While he’s a decent free throw shooter (a career 71.7 percent from the charity stripe on 3.6 attempts per game), his numbers from the field are abysmal: He shot 31.8 percent on 66 attempts from 16–24 feet last year, and he’s 27-of-99 (27.3 percent) in his career from 3. A player with Randle’s handle and speed would be practically unguardable if defenders had to respect his shot. Instead, they can just back off and force him to come into them. He’s not long enough to power through a pure athlete at the 4 like Al-Farouq Aminu. He has to raise up and shoot before it ever gets to this point:

And while his jumper may not be correctable, at least in the short term, his defensive effort is. Like most young scorers, Randle never had to expend much energy defensively in his developmental years, and could always count on his athleticism to bail him out when necessary. He will never be a good shot-blocker in the NBA, but his strength and quickness means he could be an effective positional defender who can switch screens and be a cog in a good defense. However, that means Randle has to keep his head up and understand what his responsibilities are. Count the errors in this sequence: He makes a lazy closeout on Zach Randolph, lets him drive in a straight line and doesn’t re-route him, and then falls for a pump-fake and gives up an open look at the rim:

The days of the Lakers letting Randle play through his mistakes are over. They don’t have a first-round pick this season, and they are trying to be good enough to lure elite free agents like LeBron James and Paul George next summer. Randle will have to earn his minutes. The good news is newly acquired center Brook Lopez could be the perfect frontcourt partner for him. Lopez turned himself into a 3-point shooter last season (shooting 34.6 percent from 3 on 5.2 attempts per game), which should create driving lanes for Randle in the half court. Lopez’s sheer size (7 feet and 275 pounds) means he will be more of a deterrent at the front of the rim than anyone Randle has played with. If Lopez can handle the rim protection, Randle is strong enough to keep players from establishing deep position on him and quick enough to stay in front of them on the perimeter. It’s now or never for Randle. If he can’t succeed playing next to Lopez, he’s going to end up backing him up.