It is axiomatic among coaches, scouts, and front-office types that DeMarcus Cousins is “talented.” Talk to enough of them about the NBA’s biggest mystery, and you’ll hear a couple of general thoughts over and over:

• Something along the lines of: “Man, that guy is talented, but he just doesn’t play defense at all.”

• And a spirited discussion, with widely varied opinions, on which sort of player or players Cousins “needs around him” for both Cousins and his team to succeed. Group No. 1 would slot Cousins at center and pair him with a shooting power forward — a Ryan Anderson spot-up type — so as to give Cousins room to boogie in the post and roll to the rim. Group No. 2 sees that route as an untenable defensive disaster — voluntarily playing at a size disadvantage, and relying on a ground-bound, lazy, and uninterested defender as the team’s rim protector.

This side would have Pete D’Alessandro, the Kings’ new GM and (for now) Boogie booster, chase a shot-blocking center who would seal the gaps on defense and accept a secondary role on offense. To which Group 1 retorts: “Good luck having Cousins defend power forwards as the league gets faster and rangier.”

These parallel discussions, surely whirring around D’Alessandro’s head, would make me very nervous in contemplating the max-level extension Cousins surely wants as he prepares to enter his fourth NBA season. Maximum-salaried players should at least be competent enough on defense to willingly execute a rule-based scheme and not get caught yapping at referees as Sacramento’s opponent scores yet another easy basket at the rim. They should be able to succeed within just about any roster context instead of leaving their GM to think, What in the hell do we need to have around this dude in order to win half our basketball games?

And this is what makes Cousins the league’s most intriguing mystery — the assumption that a very large portion of his on-court issues are linked to “effort” and “attitude,” and the confidence of just about every GM and coach that he will solve a riddle that has vexed so many others. Some team is going to make a giant bet, ranging from $50 million to $80 million, on the idea that Cousins is fixable outside of Sacramento’s miserable atmosphere, and that it will be the one to fix him. It’s a bet that gets at the very nature of “talent” — of whether hard work and selflessness are fully teachable concepts, and if so, how to accelerate the learning curve so Cousins can emerge as something like Zach Randolph more quickly than Randolph himself did.

How talented, really, is DeMarcus Cousins? How talented can a player be when there is something like universal agreement that he is a big, stinking minus when his team does not have the ball — a situation that occurs for half of every NBA game. Players who receive max-level extensions ahead of their fourth NBA seasons have typically lost a majority of their NBA games, since the most talented players go early in the draft, where bad teams live. Three NBA seasons on a bad team is a small sample size, fraught with issues of context, even if the player remains healthy for that entire span — as Cousins has. But even so, players agitating for a giant new contract can usually point to at least a few data points proving their value to the team — numbers that show how helpful they are in pursuit of winning games.

Even John Wall, who has missed significant time because of injury, could whip out some data and tell the Wizards, “Hey, our offense has been better with me on the floor in each of the last two seasons by giant margins, and especially last season, when I was healthy, and you surrounded me with actual quality NBA players.”

Any such team-based arguments for Cousins are a stretch, though you can find the blurry outlines of some if you look really hard. Cousins has his individual numbers, which are prodigious, and a pass-and-dribble skill set that is undeniably tantalizing for a player of his size. But three years in, those things have yet to translate into teamwide success for the Kings, and the disconnect between those obvious skills and all those losses begins with Cousins’s defense.

The Kings have ranked 20th, 28th, and 29th in points allowed per possession, respectively, during the last three seasons, and they’ve been worse with Cousins on the floor in all three, per NBA.com. Cousins is a stout post defender and voracious rebound gobbler, but he has struggled horribly at almost any part of defense that involves him moving around above the charge circle. Giving heavy minutes and a max-level salary to a big man who can’t defend is a great way to lower your ceiling unless (a) that big man is a historically great offensive player, on the level of Dirk Nowitzki or peak Phoenix Amar’e Stoudemire, or (b) you can find the perfect rim-protecting complement to that player without compromising your spacing on offense. Good luck!

Whatever team commits to Cousins will wager it can sculpt him into at least an average defender by coaxing better effort, improving his conditioning, and giving him access to better and more consistent coaching. Mike Malone, the Kings’ new head coach, figures to be first in line, and he’s a no-nonsense type fresh off helping the Warriors install a much simpler base defense that seemed to help everyone involved.

Some of Cousins’s problems on defense are clearly effort-related. He is always behind the play, a disastrously bad habit that can take on many forms. The most obvious is when he is late getting back on defense, either because he’s pouting over a missed shot or a pass that never came, or because he’s yapping at the officials over a perceived injustice. I doubt any player in the league costs his team more points this way; even Dwyane Wade thinks Cousins should shut up and get his ass back on defense.

But it’s not just the obvious lollygagging. Cousins is often late to get into proper position against the pick-and-roll, and that tardiness carries all kinds of trickle-down consequences. The Kings were a train wreck against side pick-and-rolls last season, in part because Cousins and his guards were so often on different pages when it came to defending the play. Take the Tony Parker–Boris Diaw pick-and-roll in its early stages here:

Tyreke Evans, guarding Parker, has very obviously positioned himself between Parker and Diaw — a ploy to force Parker into rejecting Diaw’s pick and dribbling toward the baseline. This is a very typical defensive tactic, and for it to work, Cousins has to be close to the baseline very early to cut off Parker’s path to the rim.

But he’s not there, as you can see. He’s still almost attached to Diaw, even though Evans has telegraphed the Kings’ strategy. This happened with comic frequency; I could put together a large photo album of Sacramento guards on side pick-and-rolls pointing for Cousins to drop toward the baseline, only to realize Cousins has barely huffed and puffed his way to the screener.

You can see Cousins in this photo beginning a panicked sprint to the place he should already be. Problem: When you have to sprint over short distances instead of sliding at a controlled pace, it’s hard to change directions a second time. Parker’s a smart player, and he realizes on this play Cousins has zero chance of stopping all that momentum going toward the baseline. And so Parker crosses back over toward the middle, blows past a reaching Cousins, and lays the ball in — plus the foul on Cousins:

Cousins is always doing his work late like this, falling behind in ways that make it much harder to do that work when he actually decides to get moving. Here’s another typical example, with Cousins hanging far behind in the paint as his man, Anthony Davis, moves up to set a screen for Eric Gordon on the right side of the floor:

Gordon is a threatening shooter, and Cousins realizes around this point that he needs to get in gear. He covers the distance to the elbow area in a (relative) flash, but he has to sprint to do it, meaning his full momentum is going toward midcourt when Gordon turns the corner around the pick. Cousins in these situations is unstable, out of control. He can’t stop and slide with Gordon, and so he is left to hopelessly reach and slap as Gordon dribbles into the lane for an easy and-1:

Everyone knows about Cousins’s foul issues. He led the league in fouls in each of his first two seasons, and no one has fouled out of more games since Cousins entered the NBA. Those fouls come not from his “temper,” or any penchant for violence, but from very bad issues of position and timing that leave him with no option but to reach desperately for steals.

Sometimes the screwups are so bad it’s hard to understand why they happen at all. You would think, for instance, that on a LeBron James–Chris Andersen high pick-and-roll, the no. 1 priority for any defense would be to contain the world’s greatest player; John Salmons certainly thought so on this play, as he pointed frantically for Cousins to abandon Birdman and slide to his left (LeBron’s right) to cut off the MVP:

But Boogie, for reasons only Boogie understood, attached himself to Andersen as if the Birdman were a Nowitzkian jump shooter, allowing James a clear path to the basket for a layup:

Whoops.

We tend to think of selfishness as something ball hogs exhibit on offense. But Cousins, to this point in his career, has been a selfish defender in lots of ways. He tries to minimize the amount of energy he expends executing the team’s scheme, and as a result, he stays very close to his own man when his team really needs him to be helping more aggressively. Even when he slides over on time to try to contain the opposing point guard on a pick-and-roll, he often leaves his help spot early, after offering only a token wave of the hand.

Sacramento’s defensive struggles aren’t all on Cousins, obviously. They’ve been bad regardless of who’s on the floor. But he’s clearly been a net negative and a major reason why the Kings have struggled so horribly against the league’s bread-and-butter play. They pulled an improbable double last season, finishing dead last in points allowed per possessions on pick-and-rolls the ball handler finishes and pick-and-rolls the roll man finishes, per Synergy Sports. Only two teams allowed more juicy corner 3s, a spot-up gold mine that typically comes after a pick-and-roll slices up a defense to the point that a third defender has to run to the rim to stop a layup. The Kings have allowed significantly higher shooting percentages at the rim and on corner 3s with Cousins on the floor in each of the last two seasons, per NBA.com.

And yet Cousins isn’t hopeless. He has nimble feet and a sophisticated understanding of how the game unfolds. He is not Stoudemire, a good-hearted and hard-working defender who still ranks among the league’s very worst defensive players because he simply has no sense of anticipation or of the court’s ever-changing 10-man geometry.

Cousins is always among the league leaders in charges drawn, and that requires a quick wit — even if trying for a charge is less effective, over thousands of possessions, than leaping to challenge a shot near the rim. Cousins is never going to be a stopper, or an elite rim protector. His team merely needs him to be decent — to follow a system of rules, be in the right place at the right time, and work hard. If Cousins can get there, he’s an asset. If he can’t, he’s the kind of pick-and-roll liability teams will attack again and again until the defense breaks. Any reasonable human being with Cousins’s raw skill set could achieve decency on defense. Can Cousins be reasonable?

The transition should be easier on offense, where Cousins too often undermines his own talents with hilariously bad judgment. He fancies himself a long-range shooter, but he cannot shoot very well. Cousins shot 32 percent on a totally irresponsible 5.2 long 2-point jumpers per 40 minutes last season, per Hoopdata.com; among 117 players who jacked at least 3.5 such shots per 40 minutes, only Rudy Gay, Anthony Davis, and Michael Kidd-Gilchrist hit a lower percentage than Big Cuz.

This should be simple: If there are more than 10 seconds left on the shot clock, you are not allowed to take a jumper longer than 15 feet. Period. Cousins’s poor transition effort hurts his team here too. He is often so late crossing half court as to give new meaning to the concept of the “trailer.” That’s fine. Marc Gasol ain’t hustling over the midcourt line before the shot clock ticks below 20.

But Gasol plays on a team constructed around a big man’s preferred pace, and Gasol’s de facto strategy as “trailer” isn’t to launch a 20-footer with 15 on the shot clock after some poor guard, seeking a release valve up top, passes him the ball. Cousins takes an alarming number of such trailing shots, and they carry the double penalty of being low-percentage and removing the Kings’ best offensive rebounder from the rim area for the inevitable miss.

Pocket a couple of these bad boys every game, and exchange them for a Cousins drive or a reset of the offense, and you’ve got something powerful. Ditto for one or two long jumpers Cousins takes after setting a pick 20 feet from the basket and just lingering there instead of rolling.

To his credit, Cousins seemed to understand this more deeply as last season went on. He should be a tremendous pick-and-roll big man, but he can only be that player if he works at it — if he cuts hard to the rim instead of screening and “rolling” nowhere. Cousins will be a very good post-up player eventually, but in today’s NBA, a max-level big man has to be more than a post player to maximize team success and keep his teammates moving. Post-ups rank only “so-so” on the efficiency scale, even when behemoths like Cousins can draw regular double-teams and pass in sophisticated ways out of them. Cousins is powerful on the block, but he’s also prone to turnovers as he tries high-risk passes, steps through double-teams, or bulls over help defenders. He likes to hold the ball for several seconds, giving defenses a chance to anticipate his move, pounce for steals, or bait him into bad passes.

Cousins has to be a more forceful pick-and-roll threat, and he seems to get that. He’s one of the only big men in the league who can catch the ball just inside the foul line, an awkward place, and do some serious damage with it. That was especially so last season, when Sacramento set things up so that Cousins could have space to operate upon catching the ball — often via side pick-and-rolls.

Here’s one version, where the ball handler continues to the baseline, drawing Cousins’s defender, and allowing Boogie to pop free into the middle of the floor:

Cousins loves to pull the jumper in this situation, but that’s a losing play. The Kings are much better off when he dribbles into the teeth of the defense, ahead of his recovering defender, and either attacks the rim or dishes to a shooter in the corner.

Here’s the same general play, only with the ball handler going to the middle and Cousins rolling free along the baseline:

Again, the Kings have cleared the right side so Cousins has space with which to play, and he should play with it via prodding dribbles, aggressive drives, and smart passes.

He’s also gotten much better at cutting straight down the middle on pick-and-rolls, and not only at a blind sprint. Those super-hard cuts are nice, and they work sometimes, but if a big man goes too quickly, he’ll lose contact with his point guard and eliminate any potential passing lane. The best rolling bigs — Tyson Chandler, Tim Duncan, Dwight Howard — have a little ballet-style tippy-toe thing going on. They can accelerate, then slow down, then speed up again — all in the span of 10 feet or so, all while reading the floor so that their point guard partner always has a passing lane to them.

Cousins made strides in this regard last season. His shot a career-high 46.5 percent from the floor, and hit at a 50 percent clip after the trade deadline. Cousins engineered the uptick in part by changing his shot selection over the last 30 games of the season. About 55 percent of his attempts in that stretch came from the restricted area, and only 28 percent came from outside 8 feet, per NBA.com. Before the trade deadline, only about 46 percent of Cousins’s attempts came within the restricted area, and nearly 39 percent came from at least 8 feet out — including a much larger percentage of long jumpers.

It was a nice stretch of smart, efficient offense, and the Kings ranked seventh overall in points per possession after the trade deadline — heady stuff for a doormat. Malone should keep leaning on that side pick-and-roll action, among other things, and the presence of two solid midrange shooters among Sacto’s big-man rotation (Carl Landry, Patrick Patterson) should unclutter the paint a bit for Cousins.

This is Cousins’s only real data point, at least in terms of team stats, in seeking a max contract: “Hey, I was really good for two months, and our team’s offense was really good at the same time! Progress!” And it’s a real, true fact.

But the team’s defense continued to stink during that span, as it has for the last half-decade in Sacramento. Signing Cousins to a max contract is gambling on his personality, always a murky thing, and on his ability to morph into an average NBA defender.

It’s a tough bet to make at this point. D’Alessandro has talked Cousins up at every opportunity, and the team’s new owner, Vivek Ranadivé, made a point of watching Cousins at the Team USA training camp last month in Las Vegas — a rare gesture for an owner. (Sources who were at those workouts said Cousins was very bad, again.) But the track record so far does not suggest Cousins is a cornerstone player. Some team is going to give him something close to the max, whether it’s Sacramento; the Lakers or some other team that will be flush with cap space next summer; or a team that trades for Cousins between now and then.

D’Alessandro should be working hard to find that trade partner willing to surrender a package that meets his needs. The Kings should be in no rush; Cousins hasn’t earned it. They control the free-agency process, and they should make him prove he’s worth that kind of deal — either so they can feel comfortable giving it to him, or to boost his trade value midseason. Either way, the Boogie mystery has some exciting turns in store.