It's hard to know if imperfections matter when a team is 10-0 in the postseason, perhaps bored knowing it can flip into another gear should any opponent decide to pose a challenge.

They matter now. The indestructible Cleveland Cavaliers are reeling, and the issues that bubbled below the surface all along -- masked by historic shooting against punchless opposing offenses -- have burst into the light: Cleveland's defense hasn't been good enough four games into an Eastern Conference finals tied at two games apiece, especially when point guard Kyrie Irving and big man Kevin Love are involved. The Toronto Raptors punched back from a 2-0 deficit with their most joyful and unburdened ball of these sloggy playoffs, and the Cavaliers couldn't locate their magical switch; it's possible Raptors coach Dwane Casey or Drake, the team's global ambassador, ran out onto the court and stole it.

The Cavs have now allowed 105.7 points per 100 possessions in the playoffs, a mark that would have ranked 22nd in the regular season, and a disturbing drop-off from their season-long performance.

Boil down their struggles into one clip, and it would look something like this:

The Raptors have ruthlessly hammered that Irving/Love wall into rubble. Point guard Kyle Lowry has destroyed Irving, especially in Game 4 on Monday, either losing Irving behind screens or juking him out of the play by faking toward a pick -- and then bolting the other direction. Those same fakes bait Love into lunging the wrong way and defending air.

This kind of stuff has been happening all playoffs, and Tristan Thompson, on the back line, is not quite fearsome enough at the basket to correct everyone's mistakes:

Things get worse when Patrick Patterson replaces Luis Scola for Toronto; Patterson is a more dangerous 3-point shooter, and as ESPN analyst Jeff Van Gundy pointed out on the broadcast, he's a Spurs-level expert at flipping the direction of his pick at the last second. Watch him sprint up from Lowry's right, as if he's going to clear a path that way for his All-Star point guard, only to pivot to the other side -- and completely flummox both Cavs guard Iman Shumpert and Thompson:

Patterson is like a phantom. The Cavs don't know where he's coming from -- or what he'll do next -- and he has them paralyzed with confusion. Another little thing on that play: Matthew Dellavedova and Richard Jefferson's coverage on Lowry at the rim, leaving both Terrence Ross and James Johnson wide open. That's not ideal; Lowry has a choice between a good shooter and a bad one. The Cavs needed one of those guys to hang back closer to Ross so that Lowry had only the least appetizing choice.

Such mistakes have dotted Cleveland's entire playoff run. It's a sin of commission and good intentions: The Cavs are trying hard, but effort without precision can lead to the same bad results as laziness.

Everyone on the court for Cleveland is working hard on this Ross 3-pointer from Game 1: LeBron James covering for Irving's bad defense with an impromptu switch, Love pitching in around the basket and everyone else scrambling to track three shooters -- Johnson, Ross, and DeMar DeRozan -- off the ball. Two of those guys are non-threats from deep. The Cavs leave the other one open.

Effort, without precision. You need both to win a ring.

But Irving and Love have been the central players in Cleveland's worst breakdowns. Opponents in the playoffs have scored 1.09 points per chance when they involve those two as the primary pick-and-roll defenders in a play that leads directly to a shot attempt, drawn foul or turnover, per SportVU data provided to ESPN.com. That would have ranked last by a mile among 119 two-man combos that defended at least 250 pick-and-rolls in the regular season, per that SportVU data set.

Zoom out to include any trip that features a pick-and-roll targeting Irving and Love at any time, and the number gets worse: a hideous 1.207 points allowed per possession, stingier than only one of those 119 duos -- the Jrue Holiday/Ryan Anderson pairing in New Orleans.

Opponents know this stuff. They are putting Irving and Love into twice as many pick-and-rolls each game as they averaged in the regular-season, a massive jump out of proportion to the slight uptick in minutes the two are playing together. These are the sort of numbers that had members of the Golden State Warriors' coaching staff quietly fretting when both Love and Irving missed last year's NBA Finals, forcing the Cavs to play superior defenders in their place.

Love started this series well, hanging in as the Raptors dragged him through two or three pick-and-rolls on every possession. But he is starting to wilt. DeRozan has even targeted him. DeRozan knows the Cavs are going to duck under picks against him, daring him to launch from 20 feet, but he's not settling. He calls for an immediate re-screen, and any defender will tell you it's hard to go back and forth under multiple picks without eventually breaking apart.

That second screen often forces Love to switch onto DeRozan, and DeRozan just rams the ball down Love's throat for layups -- especially when Love experiences a blip of confusion that leaves him a hair behind and on the wrong foot:

The Cavs are still huge favorites to win this series, but they won't beat the Warriors or Oklahoma City Thunder in the Finals with this kind of defense. Golden State has generally torn apart Love -- to the point you almost feel bad for him. Irving played the game of his life on defense in Game 1 of last year's series before getting hurt, but his performance so far in these playoffs doesn't suggest he will duplicate that for a full series.

And if they face the Thunder, who defends Oklahoma City point guard Russell Westbrook? Irving? Cavaliers shooting guard J.R. Smith? Moondog, the Cavs' canine mascot with floppy ears?

There is constant melodrama surrounding coach Tyronn Lue's rotation choices in the fourth quarter of close games. Love has played zero seconds over the past two fourth quarters in Toronto. Thompson played 22 seconds combined, a single defensive possession Monday night.

But that comes with the territory of chasing the title on a team loaded with four big men who deserve minutes in LeBron, Love, Thompson and Channing Frye. Toss in Jefferson, playing quality minutes as a Shane Battier-esque hybrid forward, and there just isn't enough time for everyone to get their jollies. That's life. That's the sacrifice you make to win championships.

Love hurts Cleveland's defense, and Thompson cramps its spacing. Toronto has done a much better job tilting its entire defense toward LeBron without leaving wide passing lanes to weak-side shooters, but that tightrope is easier to walk when Thompson is stationed just across the lane from LeBron. Every rotation is shorter, and a pile of bodies around Thompson clutter LeBron's passing lane to a drooling shooter stationed in the opposite corner.

Swap in Frye, and all of a sudden the floor is clear for everyone. The Cavs with Frye as their only real big man hit 11 straight shots in the fourth quarter on Monday -- 11 in a freaking row! -- on looks that were laughably easy. Shooting solves everything.

Whether the Cavs should really pay Love and Thompson $36 million combined to scrounge crunch-time minutes is a question for the offseason. Boston made an offer for Love at the deadline, sources have told ESPN.com, and though the Cavs found it disatisfying, the Celtics may call again if other stars higher on their list aren't available.

For now, the Cavs need to be better. They might consider taking Love off of Paterson and having him guard Raptors center Bismack Biyombo. Thompson is faster than Love and better equipped to hedge away from Patterson, cut off Lowry's driving lane and recover before Patterson can jack an open 3. Cleveland, in effect, started doing that on a couple of possessions late in Game 4; when Patterson scurried up to set a screen, Love would hang back and point for Thompson to take his place. (I call that the Brook Lopez switch, since the Brooklyn Nets have been doing it for years to remove Lopez from the pick-and-roll dance).

That has an obvious downside: Love is now on Biyombo, meaning he would be the last line of defense near the rim, and Love is among the very worst big men in the league at that. The Raptors could also just yank him right back into the pick-and-roll by sending Biyombo up to screen for Lowry, unleashing their finger-wagging version of Tyson Chandler for alley-oops.

But Biyombo might be a little easier for Love to handle: He could drop back toward the foul line, since Biyombo can't shoot. If that doesn't work, perhaps Love could trap Lowry high on the floor -- and force Lowry to slip the ball to Biyombo 20 feet from the rim, way outside the big fella's comfort zone. Cleveland trapped a bit late in Game 4, and Biyombo in Game 3 punished that strategy with a number of canny plays -- including a jump hook, off one dribble, that almost sent me flying from my chair in astonishment.

We could also see more of Dellavedova, depending on his ankle, and of Shumpert -- and more super-small lineups in which LeBron is the true power forward. A group like Irving-Shumpert-Smith-LeBron-and one of Frye/Thompson/Love brings more speed and options on the perimeter, and those groups have barely seen the floor in this series. They represent an easier way to remove Irving from Lowry without foisting the responsibility on an already overtaxed LeBron.

That said, it's time to ask whether LeBron should guard Lowry more often. The Cavs could then hide Irving on Raptors forward DeMarre Carroll, something they tried a few times down the stretch of Game 4, and revert to using Smith on DeRozan -- a matchup that has tilted more and more in DeRozan's favor as the series has proceeded.

Still, the Cavs can win this series without changing anything. That has been the theme of the the Eastern Conference playoffs: If your offense isn't potent enough to really tear apart Cleveland's best offensive lineups -- like LeBron, Love and Frye sharing the floor -- the Cavs will feel free to play those and roast you into oblivion with unstoppable shooting. The Raptors turned the tables for two games, but given how badly they struggled on offense in the playoffs before that, it's unclear if they can do it again in Cleveland.

But even if the Cavs survive this round, they'll have to play much better defense to nab the prize that has eluded a wonderful city for too long.

Other random thoughts on a suddenly compelling series:

• The past two games represent validation for the Raptors. A demoralizing sweep would have raised real questions about DeRozan, Casey and whether 56 regular-season wins meant anything in the face of three straight shaky playoff appearances.

And, yes: This qualified as another shaky playoff run before these two fantastic home wins. Toronto through Game 2 of this series had scored 98.4 points per 100 possessions through 16 games -- almost nine points below its regular-season number, and a mark that would have ranked 29th overall. Lowry was out of sorts. DeRozan was mostly a bricky disaster with a dwindling assist rate; he looked at times almost congenitally unable to find a big man rolling to the rim.

Toronto might have been one gaffe by Pacers coach Frank Vogel in Game 5 away from bowing out in the first round again, a crusher that would have raised questions about Casey's job security -- even with Toronto holding a 2016-17 option they were leaning toward picking up regardless of the Pacers series, sources say. The Raptors then limped by a Miami Heat team missing two of its three best players, though the Raptors, of course, were without their own blossoming center in Jonas Valanciunas.

But they won those series, and they found themselves here against by far the best team they've faced. Lowry is Lowry again. DeRozan still can't shoot 3s, but he has found a comfort zone zigging and zagging his way into shots that feel good for him -- and engineering switches that make those shots easier.

Good for them. If you aren't happy for their fans, you are mean or from Cleveland.

• Holy Biyombo. The Raptors have almost no means of retaining him this offseason -- they don't have his Bird Rights, so they can't go over the cap to re-sign him, and they won't have any cap room leftover if they bring DeRozan back. This has already led some rival executives to wonder if Toronto might go bold and put Valanciunas on the trade block.

I'd pump the brakes. Biyombo has been incredible, and he can do real damage as a pick-and-roll dive man surrounded by shooters. The Raptors may not have quite enough shooting if DeRozan re-signs and if they replace Scola with someone who isn't a stretch power forward. Biyombo's hands have improved, but they're still stony. Valanciunas is barely 24, with a post game that is both brutal and silky, and he has an emerging confidence on defense. Trading a guy like that because Biyombo had one inspired postseason run is dangerous.

• Casey is coming for Mike Malone's throne as the pre-eminent sideline defender among head coaches. Chill out, Dwane! Don't hurt yourself out there!

• One thing I'd explore to engage Love: more post-ups against both Scola and Patterson, and more pick-and-rolls with Irving and James. The Raptors can't switch the Irving/Love combo, meaning Love can pop or slip into the lane with a head start. Toronto can switch the James-Love combo, but when it did that, Love was smart about rolling Carroll deep into the post for quick-hitting attacks on the block.

• James Johnson has come out from hibernation and made just enough positive plays to stay relevant -- and stabilize Toronto's rotation so that Casey doesn't have to overplay Scola.

He's 4-of-6 from deep in this series, and he hurt Frye off the dribble in Game 4. Cleveland is sticking its centers on Johnson, a non-shooter, so that its speedier power forwards can scamper along the perimeter with Patterson. That's smart; it's the same way the Cavs treated Atlanta Hawks forward Thabo Sefolosha in the second round. If Johnson can squeeze out a couple of productive drives against Cleveland's bigs, that's a nice little victory on the fringes for the Raptors.

• I'd like to see Cleveland play a bit faster. The Cavs are averaging only 91 possessions per game in the playoffs, last among teams that advanced past the first round, and four fewer possessions than they averaged in the regular season.

With James guarding DeRozan on defense, pushing up the floor would perhaps trap the Raptors in that matchup on the other end. It would certainly prevent Toronto from having Biyombo stroll over to James and replace Carroll as LeBron's primary post-up defender.

Lue wants the Cavs to play faster. He told ESPN.com in March rushing it up the floor was a way to take advantage of those cross-matches and organically introduce more sharing into Cleveland's offense.

"That's why I want us to play fast," Lue said. "That's when we share. That's how it becomes fun for everyone again. Teams are cross-matched against us, and we like that. Every big man just runs back into the paint. Kevin can get open 3s out of that in transition."

• Patterson has snuck his way into some critical offensive rebounds during the playoffs -- something outside his general skill set. Against Miami's smaller lineups, he was opportunistic about darting in for tip-backs. And with about 1 minute, 40 seconds left in Game 4 on Monday and the Raptors clinging to a two-point lead, he noticed his man, Jefferson, slide in to help Frye box out Biyombo as DeRozan chucked a wayward fadeaway.

Patterson sensed his chance, rushed in uncontested, grabbed the board and dished back to DeRozan for a monster bucket.

That is part of the value of a guy like Biyombo -- and Thompson -- that goes undetected by some traditional stats. When they draw so much extra attention on the glass, it opens up creases for everyone else.

• Detroit telegraphed this in the first round, but the degree to which the Raptors are ignoring LeBron on the perimeter is alarming. LeBron is so good cutting for buckets, it's tempting to dismiss this, but it matters. He's passing up open 3s that would mark the natural end-point of possessions, and late in the shot clock, he has to drive headlong into defenders waiting at the rim for him. Even for LeBron, finishing in that sort of traffic is hard; he missed one such layup over Carroll in crunch time of Game 4.

Onto Believe-land ...