Kyrie Irving is often heralded as the Cavs' second-best player, behind only LeBron James. He is an extremely talented offensive player with great handles and a soft touch that allows him to pull up for jumpers or weave and finish through traffic.
But the numbers say Irving is actually hurting LeBron's chances at another title, rather than helping them.
That's particularly true on defense. While his defensive box score numbers aren't great, it's his plus-minus numbers that tell the larger story when it comes to Irving's defensive impact.
So what exactly is Irving doing wrong?
Irving's offense is not enough
Irving is capable of several dazzling, highlight-caliber plays per game, even against the best defensive teams. He can be a clever passer and averages better than five assists a game for his career.
He has a beautiful jump shot and great range, good for a 37.8 career 3-point percentage. (That number has been as high as 41.5 percent in 2014-15 and as low as 32.1 percent this past season.) He is also one of the best free throw shooters in the league.
Clearly, he is a plus on offense.
But when we look at total impact, Irving comes out with a real plus-minus (RPM) of minus-1.2, which ranks 36th among point guards.
To understand why, we need to look at Irving's defensive impact. This is where things get ugly.
Irving's defensive numbers tell part of the story
Irving's defensive box score statistics provide part of the information we need to understand his shortcomings.
Let's start with steals, the box score stat most often associated with perimeter defense: Irving ranks 56th among guards in steals per 36 minutes.
This is even worse than it sounds, considering he often gambles for steals. This leads to instances in which, when he doesn't get the steal, the opponent has a very easy time scoring a basket:
How about defensive rebounding? We don't always think about rebounding as part of defense, especially for point guards, but it is -- every defensive rebound ends a defensive possession, and PGs can help the team this way.
Irving's defensive rebounding per 36 minutes was ninth worst in the league at 2.4. In comparison, solid defensive point guards such as Chris Paul and Steph Curry average about twice as many per 36 minutes.
This might be less of a problem if he were part of the Cavs' rebounding effort, but he seems far from engaged in that part of the game. Most of the time he doesn't even move toward the ball, and the concept of boxing out appears to be alien to him, as shown here:
Advanced stats help tell the rest of the story
If Irving is a good offensive player, but his overall impact (as measured by RPM) is negative, how do we put that into perspective?
Irving's offensive RPM is 2.0, tied for 12th in the league among point guards. That might not rate him as highly as his fans and his skill set would, but it's still an indication of a solid contribution on that end of the floor.
But his defensive RPM is an abysmal minus-3.2, which ranks 83rd among the 85 point guards measured.
Why does his defensive RPM make him look even worse than the box score?
RPM uses adjusted plus-minus data to estimate the impact of each player on his team's net points per 100 possessions, taking into account teammates, opponents and other factors. In other words, RPM reveals whether players excel at doing the little things.
And Irving doesn't.
Irving's defensive failures include a wide array of things not covered by the box score. In some cases, it's as simple as not running back, jogging so slowly he forces his teammates to play 4-on-5 defense:
In another situation, in Game 2, he failed to keep up with Leandro Barbosa, who made an easy layup. Immediately after, Irving turned over the ball near midcourt, leading to another uncontested Barbosa layup:
His-pick and-roll defense has been subject to frequent criticism, and it's easy to see why. Often, even when matched up against Curry, possibly the best offensive player of our generation, he makes lazy decisions that lead to uncontested 3s:
Last but not least, Irving is often guilty of ball watching, forgetting to keep track of his man who then has an easy path to the basket, leading to dunks and layups:
During the regular season, the Cavaliers allowed the opposition five fewer points per 100 possessions when Irving was sitting. During the playoffs that number has ballooned to 16 points.
Even if Irving has positive offensive impact, it is almost impossible to overcome such awful defensive impact.
It has been said that defense wins championships, and Irving is one of the worst defenders of his generation. If the Cavs want to give themselves the best chance of winning titles, now and in the future, they need to find a way to get him to play D -- or if he can't, trade him.