Kevin Durant has the perfect skill set to counter how the Cavs beat the Warriors last year. (Ronald Martinez/Getty Images)

Subplots and story lines come spilling out of these NBA Finals, the third installment of an epic trilogy involving the three best basketball players in the world and, by sane estimates, seven of the best 20. The series between the Cleveland Cavaliers and Golden State Warriors can be dissected from a thousand angles. It contains its own universe. And yet, it is difficult to shake the gnawing impression that only the simplest piece of analysis will shape the ultimate outcome. News flash: Kevin Durant did not play for the Warriors last year, when they won 73 games and built a 3-1 lead in the Finals, and now he does.

Durant’s presence in these Finals, though, means even more to the Warriors than his sheer talent alone. When the Warriors lured Durant in free agency, they did not only add the second-best player in the world. They added a lethal scorer whose specific skills provide a precise countermeasure against the tactics Cleveland used to topple them in last year’s Finals. He is not just great. He is the perfect player to fix what went haywire in the Warriors’ final three games last June.

As the Warriors have morphed into a juggernaut over the past three seasons, they have built their successes – an NBA title, a 73-win regular season, a current stretch in which they have suffered one loss over 79 days – on a balletic, free-flowing offense. After falling behind, three games to one, last June, the Cavaliers managed to control the tempo and muddy the game on both ends of the court.

The Cavaliers forced the Warriors to play their game, at their pace, and the Warriors had no counter. This year, the Warriors will have a counter, and his name is Kevin Durant.

For all the Warriors’ offensive firepower – the genius of Steph Curry, the ballistic shooting of Klay Thompson, the play-making of Draymond Green – they lacked a player who excelled in one-on-one settings. The Cavs revealed that one weakness, and it led them to a shocking title.

The Cavs mercilessly targeted Curry in pick-and-rolls, using whichever player he guarded as a screener, forcing him to switch on to a ballhandler and expend energy while playing on the balky ankle he’d injured earlier in the playoffs. The ploy also slowed the game to a crawl, robbing Golden State of chaotic transition opportunities it thrives on and stifling the Warriors’ offensive flow.

When the Warriors tried to run a pick-and-roll with Draymond Green and Curry, their favored play in half-court situations, the athleticism and effort of Cleveland big man Tristan Thompson gummed it up. When Green screened for Curry in the Finals, according to the NBA’s tracking data, the Warriors scored only .63 points per possession, horrendous production for any team, let alone the 73-win Warriors.

The Cavaliers will almost certainly try to assert themselves in the same fashion this year. Except when Cleveland mucks the game up this year, the Warriors will be able to throw the ball to Durant and let him work. Last year, they did not have a one-on-one scorer. This year, they have a 7-foot scoring release valve, maybe the best on the planet at simply getting a bucket.

The Warriors will try to maintain the offense Steve Kerr instituted, heavy in ball movement and quick cuts. As tracked by NBA.com, the Warriors this season ran isolation plays on 5.7 percent of their possessions, 27th in the NBA, and used the fewest pick-and-rolls, by frequency, in the league. Durant joined the Warriors, in large part, owing to his attraction to the Warriors’ selfless offensive machine. They don’t want to play hero ball.

But now they have the option. During the playoffs, when games and possessions invariably grind down, the Warriors have already shown a willingness to cede their offense to Durant. In the regular season, Durant scored only 38.2 percent of his field goals without an assist. His points rarely came outside the natural rhythm of the offense. In the playoffs, nearly half Durant’s baskets – 44 of 89 – have come unassisted. When the Warriors’ flow does not create an open shot, Durant can bail them out.

Durant also makes it less likely the Cavaliers will stifle the Warriors when they attempt a pick-and-roll. Durant possesses the size and shooting to stifle even Thompson’s relentlessness after switching. In the 2016 playoffs, the Warriors scored .84 points per possession on pick-and-rolls. This year, with Durant in the mix, the mark has jumped to 1.06. That’s a massive leap.

The kind of playoff weapon the Warriors have in Durant grew clearest in the second round, late in Game 3 against the Utah Jazz. The Warriors fought back from a third-quarter deficit to take a tenuous lead in Utah. Up five points with the clock ticking below five minutes, the Warriors let Durant take over. He dribbled around a screen from Andre Iguodala, pulled up at the arc and drained a three-pointer – an unstoppable play, created almost wholly by Durant.

Two possessions later, the Warriors ran a similar play – Iguodala screened, and after Jazz center Rudy Gobert switched on to him, all four teammates watched Durant cook. He found a spot, the right elbow, to launch and drain a fadeaway jumper.

The best example of Durant’s unfairness, though, came in the final minute. With the shot clock at five seconds and the Warriors inbounding, they threw the ball to Durant and let him do this.

The Warriors would win by 11, as Durant dropped 38 on only 26 shots.

Durant proved to be a seamless addition within the Warriors’ offense this year. But he is also a menace outside of the system, all on his own, in the moments the machine breaks down. Last year, the Cavaliers broke the Warriors. Even LeBron James and Kyrie Irving can do it again, Durant may make it irrelevant. He is a perfect fit in the Warriors’ offense against the Cavaliers, because when needed, he can be an offense unto himself.