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With 15 games remaining in their regular season, the Miami Heat are still fighting for their playoff lives.

The Heat currently sit in the Eastern Conference's seventh seed, but four other teams are breathing down their necks to take one of the East's final two postseason slots. The Boston Celtics and Indiana Pacers sit just one game back of Miami. The Charlotte Hornets are a game-and-a-half back, while the Brooklyn Nets are a distant three-and-a-half games behind.

That's a whole lot of competition for just two playoff spots. And both Boston and Indiana have been hot lately—each has gone 7-3 in its last 10 games.

Still, as difficult as the road may be for the Heat, there are a few reasons to believe they'll be one of the teams battling it out in the 2015 postseason.

Small-Ball Lineups

The Heat are averaging 103.9 points per 100 possessions since acquiring Goran Dragic, good for eighth in the league over that span.

Miami has actually improved its offense since losing Chris Bosh for the season—it was averaging 101.5 points per 100 possessions prior to the trade deadline. Dragic's arrival obviously has a little something to do with that. But so too do all of the small lineups Erik Spoelstra has been trotting out lately.

With Bosh out, the Heat have had to scrap most of their traditional lineups and start experimenting with a lot more small ball. Luol Deng, Michael Beasley and even James Ennis have gotten a lot of burn at the 4 recently. Miami has been awesome, especially offensively, when it partners one of those wings with Chris Andersen or Hassan Whiteside.

Since the trade deadline, the Heat's small lineups have scored 109.2 points per 100 possessions (and allowed 104.8), per NBAwowy.com. That would tie the Golden State Warriors and Los Angeles Clippers for the best mark in the league over the course of the season.

The Heat aren't a great shooting team (they're hitting 34.1 percent from deep), but they're at least good enough to space the floor for Whiteside and Andersen. And that's what's most important.

Miami is one of the league's best at paying off big men when they roll to the rim. And as opponents are learning, those cutting bigs are even harder to stop when they're surrounded by shooters on the wings.

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Whiteside and Andersen are also good decoys. They pull defenders toward them with hard rolls to the basket, opening up driving lanes for the Heat ball-handlers.

Dragic has been particularly deadly in these groups. Nearly 46 percent of his shots are coming directly at the rim, and he's connecting on 74.4 percent of them, per NBAwowy.com. He and Dwyane Wade are also generating a ton of easy three-pointers when they turn the corner on screens or get to the rim.

Recently, Spoelstra has gotten even wackier with his lineups, throwing Beasley out at center for extended stretches. It'll be interesting to see if he sticks with those groups. They could be a real weapon moving forward.

As you might imagine, they're getting killed defensively (134.2 DefRtg). But they're also scoring an absurd 142.9 points per 100 possessions, per NBAwowy.com.

Playing Beasley at the 5 turns one of his biggest weaknesses—his love of deep jumpers—into a relative strength. Deep twos may not be the most efficient of shots. But when he's at center, they serve the added purpose of pulling opposing bigs out of the paint.

His off-the-bounce game also becomes much more dangerous in those lineups. There simply aren't a lot of 5s, no matter how quick, equipped to deal with him off the dribble.

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Defense

The Miami defense has been very good since the trade deadline. The Heat are allowing 100.4 points per 100 possessions over that span, just shy of a top-10 rate.

That defense, as always, is built on the strength of its ability to smother pick-and-roll ball-handlers. Bosh was one of the keys to the Heat's blitzing defensive scheme, and as such, they haven't been trapping quite as aggressively recently. But they're still very dangerous when they do.

Only the Milwaukee Bucks and Atlanta Hawks have defended pick-and-roll ball-handlers better than the Heat. Opponents are shooting just 37 percent against them in those play types and are turning the ball over 22.1 percent of the time, a huge number.

Generating those turnovers is crucial. They lead to easy points and, just as importantly, prove that Miami isn't giving ball-handlers clean passes to roll men.

The problem with blitzing is that if opponents are able to get the ball out to their rolling big, Miami is essentially left to defend four players with three men. To survive defensively in those situations requires perfect, frantic rotations. This year's Heat aren't as good at recovering from those situations as in years past, but they've shown some recent improvement.

Roll men are naturally shooting high percentages against Miami, as they're the ones with the best chance of cashing in on any defensive miscues. But the Heat are limiting them to just a handful of shots (6.1) per game and doing a great job of staying home on three-point shooters as well.

The real danger isn't the roll men themselves so much as it is the open three-pointers they can generate with just a few passes. Miami, to its credit, has done a great job defending the three-point line. They're allowing 34.3 percent shooting from deep and closing out extremely well.

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Top-Shelf Talent

This is purely anecdotal, but there's something to be said about how much high-end talent the Heat have.

Again, Miami has only 15 games remaining in its season, and it'll have the best two or three players on the court in at least two-thirds of those games. That's hard to ignore. Because while everything detailed above—scheme, flexibility, lineup combinations, etc.—is important, talent ultimately trumps all.

Just take a look at the Heat's recent 108-104 win over the Portland Trail Blazers. Miami's role players tallied a combined 20 points on 21 shots.

Its four best players—Dragic, Wade, Whiteside and Deng—scored a combined 88 points. Dragic racked up 20 points and 11 assists. Wade had 32 and six assists. Heck, Whiteside only had 12 points but chipped in six blocks as well.

The teams Miami is battling for the East's final playoff spots simply don't have players (or at least not many) who can take over games like that. The Heat have three of them. How can you bet against them?

All statistics accurate as of 3/19/2015 and courtesy of Basketball-Reference or NBA.com/Stats unless stated otherwise.