They always say the playoffs are about matchups. But you have to have the personnel that not only can take advantage of those matchups but the mindset to exploit them. 

That's what makes Kyrie Irving so valuable to the Cavaliers

The Cleveland Cavaliers won Game 4 of the Eastern Conference finals on Tuesday, 112-99 over the Boston Celtics to take a 3-1 lead in their best-of-seven series. Irving was electric, going for 42 points on 15-of-22 shooting, scoring 21 points in the third quarter alone to lead the Cavaliers back from down 16 points. It was an incendiary performance, brought about not just by his crack shooting, but by unbelievable, artful, brilliant finishes at the rim. 

It also highlights how much the Celtics still need a rim protector. Al Horford collected a lot of blocks this season, but he's still not a rim protector that guards fear in any capacity. Irving exploited this over and over. He made ridiculous, crazy finishes that maybe no other player in the league can make, but the fact that he had the confidence to do so, over and over again, shows something about what the Celtics are missing beyond the injured Isaiah Thomas

Horford just doesn't have the physical profile to deter guards at the rim, and the result was Irving attacking over and over. He had to adjust, and make crazy plays, which he can do because he's Kyrie Irving, but it still showed a relentlessness at attacking a weakness. 

Irving faced such little resistance at the rim he was willing to go for an alley-oop layup that Tyler Zeller was helpless to stop. 

When the Boston bigs did show, they did so too late, giving up and-ones when Irving adjusted and twisted in mid-air like 2006-era Dwyane Wade

And some were just individual brilliance. This Euro-step leaning fadeaway floater thing he does is 100 percent Irving. 

What this tells us about a series that is accelerating toward completion after a brief stoppage in Game 3 is two-fold. One, this is what makes Irving so fitting for this Cavs team. If you just surrounded LeBron James with complimentary pieces, your team can go apart like it did in Game 3 and the first half of Game 4 when James struggled mightily. Instead, Irving led them back, giving James the moment to help go out and close it. 

The Cavs don't have a complimentary playmaker to assist LeBron, like Wade was. Ironically, Irving, a point guard, is way more of an individual creator and isolation scorer. But that's a huge weapon when you can do it not only with his efficiency, but with his ruthless persistence of attacking these matchup problems. Both the Bulls and Wizards knew the Celtics had this deficiency, but didn't attack it consistently, even when it was exacerbated by Isaiah Thomas' defensive shortcomings. They went away from it, tried to run their offense. 

The Cavs, instead, sicked Irving on the Celtics' weakness like a computer virus attacking a vulnerability. And once he was in the system, he shut down the whole thing. That relentlessness, that determination to exploit weaknesses, that's what makes Irving great for this Cavs team, and what makes him such a weapon in a very-likely matchup vs. the Warriors, just as he was last year in exploiting a mismatch by burning Stephen Curry

Two, Boston's problems aren't just the lack of Isaiah Thomas or perimeter size. It's interior, too. Horford has had a tremendous season in Boston, and played the five really well in Atlanta for a decade. But it becomes more and more apparent that for all the talk of a superstar wing, the Celtics might need a big man inside to protect the rim like Tristan Thompson does just as much.