Despite being regularly criticized for not moving the ball enough, not having enough shooting, and using generally poor shot selection, the Thunder own the NBA's second most efficient offense. They score over 113 points per 100 possessions, better than every team that did not set an NBA record for total wins. They score by having Russell Westbrook drive from the top of the key, where he is at his most efficient when he draws the defense and finds an interior pass -- which leads to 1.26 points per chance, and creating transition opportunities where they score 1.33 points per chance (fourth in the league) when Kevin Durant is on the floor.
The Westbrook drive -- whether out of an isolation or pick-and-roll, creates catch-and-shoot opportunities for Durant and Dion Waiters or layup opportunities for Steven Adams and Enes Kanter. In transition, they are one of the most dynamic teams in the league as no player is better at converting the shots that they get in transition than Durant. Quantified Shooter Impact measures a player's ability to convert shots relative to an average player, and Durant leads the league with a qSI of 26.1 in transition -- meaning that given the shots he gets, he has an eFG% that is 26.2 percentage points higher than an average shooter.
The Thunder still lack long-range shooting, however. Their best 3-point shooter this season has been Anthony Morrow, but he ranks 36th in the league in eFG% on 3-point shots for players with at least 150 3-point attempts, and he has played a grand total of 49 minutes in the playoffs and taken only 13 shots. Durant led the team in 3-point attempts, but ranked only 49th in the league in eFG%. Westbrook was second on the team in attempts and ranked 147th in eFG%.
While the Thunder certainly lack the Warriors' shooting prowess, their true weakness is on the other side of the court. Defensively, the Thunder rank 13th in the league in defensive efficiency, and while that is better than average, it is hardly championship level. The Thunder do a good job of protecting the rim when they get shots -- holding opponents to a qSI of -2.2 on shots in the paint, third-best in the league. But they struggle to keep opponents out of the paint, surrendering 42.6 shots in the paint per 100 possessions -- third most in the league. They also do a poor job of limiting their opponents transition offense in both volume and efficiency. They have given up the seventh-most transition opportunities, and they allow opponents to take 77.6 shots per 100 transition possessions -- only the Knicks allowed more.
Heading into the Western Conference finals, the Thunder have the daunting task of facing what is arguably the best team in NBA history in the 73-win Golden State Warriors. Despite the Warriors' historic shooting and attacking defense, the Thunder do have some opportunities that they can look to exploit. On the offensive side, the Warriors have most frequently matched up Klay Thompson against Westbrook, but this is a matchup the Thunder can exploit. In the 89 possessions that Thompson has guarded Westbrook this season, the Thunder have scored at a rate of 127 points per 100 possessions. One of the main avenues for them to exploit this matchup is on pick-and-rolls. Typically, the Warriors have done a great job limiting the value of Westbrook in a pick-and-roll at the top of the key, letting the Thunder score only 0.9 points per chance, but when Thompson is guarding him, the Thunder are scoring 1.2 points per chance from pick-and-roll's at the top of the key. That is still not quite Westbrook's season average, but still very effective.
The Adams versus Andrew Bogut matchup is also one that has been beneficial for the Thunder. When those two have been matched up, the Thunder are scoring 117.1 points per 100 possessions -- part of that is because when Bogut has guarded Adams this season, Adams has been very effective as the screener in pick-and-rolls, getting the Thunder one point per chance.
The biggest threat the Thunder face on the offensive end comes in the form of Andre Iguodala, who will likely be matched up against the thunder's most efficient scorer, Durant. Among players who took at least 1,000 shots this season, Durant ranks fourth with a 55.9% eFG, behind only Stephen Curry, Thompson, and Kawhi Leonard, despite taking the second hardest shots by qSQ (which uses the location and movement of the shooter and defenders, as well as the type of shot to measure the eFG% of an average player on that shot) of anyone in the top 10 in eFG% this season (Chris Paul took the hardest shots and was 10th in eFG%). When he has been marked by Iguodala this season however, this incredibly proficient scorer drops down to a 46% eFG which is Jamal Crawford/Evan Turner territory. Typically about 25 percent of Durant's shots are pull-up jumpers, and he has a 52 percent eFG on those shots -- below his average. Iguodala, however, has forced Durant to take pull-up jumpers far more frequently (40 percent of his shots) and has defended them better (25 eFG%). So the Thunder will need to minimize the opportunities for the Warriors to put Iguodala on Durant, and Durant will have to look to pass out of that matchup instead of taking the pull-up jumper of last resort.
Defensively, the Thunder have to solve the obvious puzzle that is Curry. He can shoot from anywhere, which causes the defense to stretch so when he does pass, his teammates have the highest quality shots by qSQ in the league. Plus he has developed into one of the best finisher's in the paint in the league. For the most part, the Thunder have not been able to slow Curry down. One of the Warriors' favorite plays is the Curry/Draymond Green pick-and-roll. When Westbrook is guarding Curry over the past two seasons, that has led to one point per chance for the Warriors.
The bulk of the scoring though comes from situations in which Westbrook switches off of Curry on the pick. When Westbrook switches to Green, the Warriors are scoring 1.2 points per chance. The switch is setting up a mismatch on Curry that makes it easier for him to get either a high quality shot, or find his open teammate. When Westbrook goes over the pick, however, and stays with Curry, the situation changes significantly. Now the Warriors are scoring only 0.4 points per chance. If you look at Curry's shooting against the Thunder, it is further evidence that the Thunder's key to slowing him down is to make sure Westbrook never leaves his side. Curry has a qSI of plus-6.7 against the Thunder over the past two seasons, and when any wing or guard not named Westbrook guards him, that goes up to plus-9. When Westbrook is guarding him, Curry takes more pull-up jumpers and his qSI drops to plus-2.1 -- still above average, but much lower than any of the Thunder's alternatives.
If slowing Curry down is priority No. 1, then priority No. 1a is probably making sure that Adams and Serge Ibaka are in the game. When the two of them are on the floor, the Thunder defense is the best in the league at protecting the paint, with a qSI in the paint of minus-4.1. To give that some context, the Warriors would be second in the league with a qSI of minus-2.8. Without those two on the floor, however, the Thunder struggle to defend the paint, allowing shooters a qSI of plus-1.2 -- which would be the worst in the league.
Keeping them both on the floor will be a challenge given the Warriors' ability to create mismatches with their small lineups, but if the big guys can keep up, then the Thunder have a chance to bring the Warriors' offense a little bit closer to earth.