On May 19 of last year, the Lakers hosted the Thunder in Game 4 of the Western Conference semifinals. The score was tied at 98 and the Thunder had possession. With about 26 seconds remaining, James Harden handed off the ball to Kevin Durant. The design was a pure isolation play and the idea was to kill as much clock as possible while getting a decent Durant shot. Durant took the ball and calmly dribbled some seconds away. At the 20-second mark, with 10 left on the shot clock, Durant bounced the ball on the “L” in the Lakers midcourt decal. Still calmly dribbling, he finally squared his shoulders to face the basket; with the other eight players scattered around the perimeter, it would be him against Metta World Peace in the game’s most vital sequence.

Durant continued his dribble as he approached the top of the arc. In a single smooth motion that was equal parts nonchalant and cold-blooded, he crossed the ball through his legs to his left hand, stuttered his feet, and rose up from the top of the arc to win the game. The 23-year-old had just launched a devastating 3 to conquer Kobe Bryant’s Lakers on their home floor. It was the least frantic version of “hero ball” ever; it looked like a warm-up move that he had practiced a thousand times before, and it was.

In this instructional video, Durant explains that when he’s at the top of the arc and a defender is “down and ready for me to go to the basket, I give him a wide [stutter-step] so he can get a bite on it, then I pull up.” That looks really familiar.

Back at Staples, when Craig Sager asked him how confident he was about getting a good shot with World Peace defending him, Durant said, “I knew he was gonna play off me just a little bit. … I saw some airspace and was able to knock it down.” Practice makes perfect.

Kevin Durant made his NBA debut in Denver on Halloween night way back in 2007. It was about a month after his 19th birthday; Durant played 32 minutes and scored 18 points on 7-of-22 shooting. The Nuggets won 120-103, but after the game the questions were all about the 19-year-old Sonics rookie. The Nuggets’ Allen Iverson said, “The future is bright for him and the sky’s the limit for him. He’s going to be great.” Iverson was right — five and a half years into his career, Kevin Durant is the best scorer in the NBA and only getting better.

In 2013, we take it for granted that Kevin Durant is a great NBA shooter. But the truth is that not too long ago, this simply wasn’t the case. During his rookie season, Durant struggled mightily. Although he was extremely active from midrange, he shot only 39 percent from there. Beyond the arc he shot a measly 29 percent, far below league average. To really appreciate the historic Durant season currently unfolding, you must first be aware of how far he’s come since Halloween 2007.

Durant’s first NBA coach was P.J. Carlesimo, but this was a poor fit. Carlesimo didn’t fare well in Seattle/OKC in part because he inherited a rebuilding team that had just traded away Ray Allen and Rashard Lewis, and in part because he couldn’t figure out how to use his young star. Although it’s seldom discussed these days, Carlesimo tried to use Durant as a shooting guard you know, one of those 6-foot-10 shooting guards with a 7-foot-4 wingspan. As a result, KD spent his time on defense chasing much smaller players as they weaved through countless screens. On offense, Durant was used as a catch-and-shoot specialist. His rookie shooting chart reveals a few things:

1. He was most active on the right wing and along the right baseline.

2. His shot behavior was asymmetrical and heavily weighted toward his right.

3. His offensive game relied more on midrange jumpers than on drives to the basket.

After Durant’s rookie season, the Seattle SuperSonics relocated to Oklahoma and became the Thunder. But the Thunder started 1-12 and Carlesimo was fired after the team lost its 10th straight game — a Friday-night blowout against the New Orleans Hornets. When Scott Brooks was named interim head coach, the first thing he did was relocate Durant from shooting guard to small forward. In the Saturday-night rematch against the Hornets, Durant made his debut as a small forward: He scored 30 points and made 69 percent of his shots.

Since his rookie season, Durant’s improvement has been both steady and drastic, but it boils down to two related factors: His shot selection is better, and his field goal percentage has increased everywhere. I spoke with Durant last week and asked him how his approach to the game had changed since his rookie year. He told me the key difference is “knowing where the best shots are and knowing where my spots are.” This knowledge has made him a much smarter shooter. “When I was a rookie I was shooting lots of contested 3s, coming off curls shooting with two hands in my face. I think I’ve learned what are really good shots and the easiest ways to get points. I’m always looking for the easy points.”

Durant’s improved ability to handle the ball and attack the basket has improved his chances for easy points. And there are no easier points in the NBA than free throws. He’s shooting 9.5 free throws per game and making better than 90 percent of them. He’s also overcome the temptation to take the first possible shot available to him during a possession, a development that likely explains why he’s shooting fewer midrange shots this season. “I give up good shots in favor of great shots,” he told me. “I’ve been mixing it up in different ways. If I don’t go to [my midrange shot], that means I’m scoring well from other places on the floor.”

It’s true. This season, Durant is scoring more effectively in the “NBA Jam” zones — at the rim and beyond the arc — while taking fewer midrange shots. From this spatial perspective, in 2010-11 Durant was a 23/50/27 guy — meaning 23 percent of his shots were close-range shots, 50 percent were midrange shots, and 27 percent were 3-point shots. This season he’s a 34/41/25 player. He’s given up good shots in favor of great ones.

Durant’s performance close to the basket has changed, too. Although he makes 67 percent of those shots — the identical percentage he made two years ago — he’s taking a greater proportion from close range. Just two years ago, only 23 percent were close to the basket. Last season, that number jumped to 32 percent, but consequently his efficiency in this area dropped to 63 percent. This season, 34 percent of his shots are close to the basket and he’s making 67 percent of them. He’s managed to increase his activity near the hoop and also regain that efficiency when less active there. In addition, he draws a majority of his shooting fouls in this zone, which helps him get those 9.5 free throws per game. In other words: Good things happen when KD is close to the basket.

Durant’s newfound close-range activity has come at the expense of midrange shooting. He’s taking only 41 percent of his shots from midrange — down from 52 percent in his rookie season. As recently as two years ago, Durant was still a midrange maniac. In 2010-11, 50 percent of his 1,500 shots occurred between eight feet and the 3-point line. He made 42.5 percent of them — not bad, but unremarkable. This season he has stopped taking as many long 2s (a.k.a. “the Josh Smith shot”). As a result, his midrange field goal percentage is a career-best 47 percent. The best way to improve your shooting numbers? Stop shooting like Josh Smith.

In terms of efficiency, however, the biggest overall improvement in Durant’s shooting is unquestionably behind the 3-point line. As a rookie, Durant shot only 15 percent of his shots beyond the arc, and made only 29 percent of them. This season he’s taking 25 percent of his shots there and making 42 percent of them. He’s currently 13th in the NBA in 3-point shooting efficiency; that’s good company.

Durant’s overall field goal percentage has increased because he’s a better shooter, but also because he’s a smarter shooter. It’s staggering to see how and where Durant’s shooting has improved on the court.

Although it’s tempting to attribute these improvements to the simple fact that he’s a freakishly talented guy, that sells him and his work ethic short. The NBA is full of freakishly athletic and talented men, but few if any work as hard as Durant. Durant’s evolution has as much to do with his own grind as anything else. When I recently asked Durant’s shooting coach, Justin Zormelo, about his work ethic, he told me his pupil is “second to none,” and that “all the proof you need is how far he’s come at age 24.”

If you ask Ray Allen about his favorite shot, he’ll tell you it’s the left-corner 3. When you ask Durant, you don’t just get a shot, you get a sequence: “It starts at the top of the key, left-hand side — dribble, dribble, stop and pop — and it’s kind of hard for defenders to recover because I can go all the way to the rim. So I just pull up and do a little fade right around the elbow. I’ve been working on that so much, I feel like that’s my go-to shot.” The answer reveals not only that Durant loves that pull-up fadeaway near the elbow, but also that the “shot event” for him begins a few dribbles before the actual jump shot occurs. Similarly, it highlights perhaps the most underrated part of Durant’s game: his ballhandling.

The reason World Peace gave “airspace” to Durant in that playoff game in May is because he was scared KD would use that dribble-dribble move and blow right past him. Pure shooters like Kyle Korver or Steve Novak don’t get that kind of spatial respect — and that’s the difference between a shooter and a scorer in the NBA. Kevin Durant is not merely a great shooter; he’s special because he can shoot like Korver and dribble like Kyrie (almost); oh, and because he’s 6-foot-10.

A lot of people talk about the 50-40-90 Club, mostly because it’s only been accomplished nine times. The idea is that only the most elite NBA shooters can hit 50 percent from the field, 40 percent from 3, and 90 percent from the line. While it’s true that these three thresholds are very hard to overcome, the club’s criteria are also indicative of the status quo of shooting evaluations in the NBA. We obsess over percentages and neglect the value of volume. The idea that Durant is on pace to join this club is certainly impressive, but the fact that he’s doing this while shooting as much as he has been is ridiculous. As Zach Lowe pointed out a month ago, while 50-40-90 is extremely impressive, to simply lump this Durant season in among all the other 50-40-90 campaigns is selling KD short. He’s doing this while leading the league in scoring.

Only one other person in NBA history has combined the volume and efficiency that we’re seeing from Durant this season: Larry Bird in his prime (at ages 29 and 30). Durant, unsurprisingly, is a huge fan of Bird’s. “I like his efficiency and how he played within the pace of the game,” Durant said. “How fierce he was. How he played with his teammates. His edge. How competitive he was.”

Sounds familiar. Except Durant is only 24. When Bird was 24 he averaged 21 points per game while shooting 48 percent from the field and just 27 percent from 3. Although the league was admittedly very different back then, it’s not as though we expect players to peak at age 24. If this isn’t it, what will Kevin Durant’s prime look like? I asked Zormelo what Durant could possibly improve on going forward. “Every single thing,” he said. I pressed and asked if he could make 50 percent of his 3-point field goals: “For sure. At 24 he’s already one of the smartest players in the league. People don’t understand how smart he is. He’s the most efficient player in the world with the ball in his hands. In terms of points per possession, he’s the most efficient player in the league over the last two years.”

Offensively, Kevin Durant has become a once-in-a-generation, pick-your-poison kind of foe. The real growth areas for him are on the defensive end of the court, passing the ball, and on the boards. His coaches will tell you that his defense is improving every month, and if his January numbers offer any clues, the passing and rebounding numbers are looking up, too. If it weren’t for LeBron James, Kevin Durant would clearly be the best player in the league. The way things are going, it may not be long before he becomes just that.