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He arrives on time at a high-end steakhouse in downtown Cleveland wearing a Nike sweatsuit, disrupts his meal to mingle and take photos with fellow patrons, and when asked if he wants to finish off two appetizers, he gladly offers his guest to eat both.

So what could be so dangerous about Australian Matthew Dellavedova, who has quickly built a reputation in some NBA circles for being too aggressive? Delly, a key energy and defensive catalyst for the Cavaliers, downplays that notion over dinner on Sunday.

"When [the Al Horford incident] first happened, I was pretty annoyed by people calling me dirty because I think it's a pretty serious thing to say that about somebody in the sporting world," he tells Bleacher Report over calamari, crab cakes and his order of the New Zealand lamb rack at XO Prime Steaks. "Because no one was talking about the [Kyle] Korver loose ball until the Horford thing happened. That's why I was kind of a bit perplexed by that, and then I just pretty much turned off my phone and didn't really watch TV."

Dellavedova's 19-point performance in the Cavaliers' close-out win in Game 6 in the conference semifinals and his physical hustle plays against the Bulls and Hawks have made him a cult hero in Cleveland. The team shop sold out of his merchandise, and local rapper Mizzery Jones of A.I. produced "Hustle Like Delly," with the words "I'm just tryin' to stay ready, 'til I die I'm gonna hustle like Delly."

The 24-year-old Dellavedova wasn't aware of the song, as he's turned off the outside noise.

"My life is just the same," he said. "I still do the same things. I spend a lot of time at Chipotle."

But when you dig deeper into his life in Cleveland, you discover that his competitive nature growing up in country Victoria in Australia started with simple board games, which ignited an approach to take calculated steps on the court to win at all costs.

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Monopoly. Trouble. Uno. These are the games a young Dellavedova and his parents, Mark and Leanne, and two little sisters, Yana and Ingrid, played at home. These days at his downtown Cleveland apartment, he's into backgammon, Bananagrams and Sequence. He plays them regularly with his girlfriend, Anna, a former volleyball player he met at Saint Mary's College of California; his closest friend on the Cavaliers, Joe Harris; and family and friends from Australia when they visit.

"My mom and dad are very competitive people, whether it's sport, which they both played, or board games," said Dellavedova, who's a sixth-generation Italian. "I've just always had that feeling that I needed to win at everything that I've done. I've managed to try to scale it back a little bit when it comes to Monopoly and different board games, so it didn't become a problem. I would get too competitive over things that don't really matter. It's funny because Anna is competitive like me."

Dellavedova unleashed that competitiveness in multiple sports: Australian rules football, basketball, field hockey, soccer and tennis. While he played football at the junior level—his second most serious sport at the time besides basketball, which he started playing at four years old—he learned two aggressive techniques that helped him on the court: one, to corral offensive players to the sideline, keeping them away from the attacking middle of the field; and two, to create a double action out of a loose ball.

"In Australian football, there's a way you dive on a ball so you can get it to your teammate as quick as possible," he said. "We'll use the Korver example. I dove on the ball, and I quickly tried to grab the ball and then quickly sit up and try to find a teammate. If you just dive straight for the ball, what are you going to do on your belly with the ball? It's going to end up either a jump ball, or you burn a timeout."

When Dellavedova arrived at the prestigious Australian Institute of Sport (AIS) training institution in 2007 in Canberra—where fellow NBA Aussies Aron Baynes, Andrew Bogut, Dante Exum, Luc Longley and Patty Mills attended—he was locked in on obtaining that "1 percent edge," his former AIS coach Paul Goriss said.

That included seeking out Debbie Savage, a former Australian standout runner who works at AIS teaching the Pose Method of running, which is a style of falling forward through a gravitational torque while pulling the support foot rapidly from the ground using the hamstring muscles.

Like Savage, Dellavedova had issues with his feet and shins from running too heavily. "It always looked like he was running in mud," Goriss said. About four days per week at AIS before his basketball practices, he would work with Savage for about 45 minutes on running, moving laterally and changing directions.

"The technique really did help me become lighter on my feet and helped me become quicker," he said.

In addition, Dellavedova kept a daily diary at AIS, charting things like his shots and training sessions. He would mark down what he needed to improve each day and then his strengths and weaknesses after every practice.

"It was an amazing opportunity to go to AIS," he said. "It definitely helped me become the player and the person I am today. ... I'm sure a lot of the Australians in the NBA, Europe and the Australian league would trace a lot of their success back to the Institute of Sport because it has just been a great base to learn from."

The 6'4" Dellavedova says he can dunk, but athleticism has never been his thing. He made his mark in what has become his NBA specialty: scrappiness.

"He's a street fighter," said 76ers coach Brett Brown, who previously led the Australian men's national team. "Delly would make us run out of canisters of ink charting the effort chart we do [for our players in Philly]. He just epitomizes that Australian spirit. They just fight, man. They just have an incredible way about them as a people, and he's a hell of a story."

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The first time Dellavedova knew defense had to be his staple came after Brown picked him for the U19 team in 2009. That summer Australia had a game against New Zealand, featuring then-28-year-old Kirk Penney, who had a brief stint in the NBA. And Dellavedova, 10 years younger, was on the bottom of his team's 12-man roster.

"I ended up guarding Penney off a lot of screens and getting beaten up," Dellavedova said. "The international game is a lot more physical, especially the Australia-New Zealand rivalry games. That's how it started off with the national team in Australia, and then my role kind of grew from there. Having that defensive presence helped give me time to work on other parts of my game to eventually take on a bigger role with the national team."

His knack for defense also convinced him he could play in the NBA.

"I was playing on the national team, and we had a game versus France [in 2011], and I got assigned to Tony Parker," he said. "I just felt like I defended him well, and I was like, I feel like I can definitely hold my own at that NBA level."

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At Saint Mary's for four years, he blossomed beyond defense, becoming the school's all-time leader in career points. In coach Randy Bennett's system, Dellavedova mastered the middle pick-and-roll and developed a unique floater game, both with lob passes and finishes in the paint. However, entering the 2013 draft, his former coaches say there were questions about the confidence, consistency and range with his shot—now positives playing more off the ball alongside LeBron James and Kyrie Irving.

But at the time, those factors led to him going undrafted and starting the process of scrapping from the bottom again—first in the 2013 Vegas Summer League with the Cavaliers. Then it was later during the season in practices, going up against Irving, who was born in Melbourne.

"When he first came, it was almost a fistfight every day in practice, every single day," Irving said after a pre-Finals practice in Cleveland. "It wasn't that he was trying to be dirty or intentional or anything like that. It's just the way he is. It's just his nature. It's that Australian blood that he has in him that's running deep, and it's just deep-rooted.

"They just are nonstop. They're going to keep coming at you and whatever they have they're going to throw at you. So I just truly appreciate having a competitor like that. I love him."

Dellavedova added, "It would get very physical at times because I was trying to defend him as well as I could, and we both just wanted to win the drill. He's a really tough cover. It does make it a little bit easier to try to guard other people in games."

In the Eastern Conference Finals, Dellavedova's 3.97 average foot distance from his defender was the best mark for a non-center with a minimum of 50 shots defended, according to Pro Basketball Talk's Kurt Helin and NBASavant.com. And his defensive rating went from 103.9 in the regular season to 95.0 in the playoffs, according to NBA.com. Taking a page from his Australian rules football days, he typically sticks to his man full court and constantly shows his hands—unless an opponent drives, and then he'll guard them with his chest so he can avoid a foul.

"He's a guy that's possession by possession," Goriss said. "Whatever he has to do in that possession, he will. To me, that's not dirty; that's just a competitor."

Dellavedova's liking for close-up contact has led to a total of seven stitches on his forehead over the years and getting cut a few times underneath his chin, resulting in a few more stitches.

"That's why I have a beard, because it's a bit of protection," he said, smiling.

Before the Hawks series, Cavaliers Player Development Coach Mike Gerrity uploaded plays of Dellavedova's specific opponents onto his iPad. Delly said that helped a lot, as he noticed that point guard Jeff Teague liked to reject a lot of screens and drive the other way.

"I thought I did a pretty good job of not letting him do that and try to make sure he was always using the screen," Dellavedova said. "That's something that you pick up on the tape."

NBA scouts have noticed.

"He plays every minute like it's his last," a Western Conference scout said. "He's gritty and rugged, and he's very intelligent. I really think he has more of a psychological effect for the Cavs more than anything right now. He's gone from a guy that probably shouldn't have been on the floor early in the season to one of their key players. There's nothing exceptional about his game, but he plays with high energy and makes open shots. That's what most coaches want from their role players."

An East scout added, "I think of that old saying 'true grit' regarding Dellavedova. He's been a bit of a lightning rod for controversy, but, hey, John Stockton wasn't known as being the nicest guy on the court either. ... Delly fights over the top of screens, sticks his nose in and gets rebounds and 50/50 balls—winning plays."

So what's the game plan against Curry and Co.?

"Obviously he's the big key for Golden State," said Dellavedova, who has film to watch of the current MVP, as well as Leandro Barbosa, Shaun Livingston and Klay Thompson, "so we have to try to limit his shot attempts and his touches because he creates so much offense through shooting, passing and penetration. He's going to hit tough shots on people, but as long as you can get a contest, that's all you can do. Another big thing with Curry and Thompson is limiting their threes off offensive rebounds."

It hasn't hit Dellavedova yet that he's in the Finals—"It just feels like another series against another good team," he said—but he'll soon feel the buzz from his family, flying in from Australia, and local friends who will be in attendance. Saint Mary's is only 20 miles from the Oracle Arena.

"He's been great for us, and I know he's happy to be back here, too, playing college ball here," James told reporters on Wednesday. "I love Delly, what he brings to our team—just toughness and grit, determination. He just tries to beat all the odds."

In Australia, the excitement for the Finals is just getting started.

At the popular Kickz101 sneaker store in Melbourne, the hottest NBA jersey off of the rack is Stephen Curry's. James' and Irving's are also hot sellers. One jersey that owner Matt Hammond wishes he had to sell was Dellavedova's, but some local fans have asked for custom orders.

Courtesy of Matt Hammond

"There's a lot of hype down here for the NBA at the moment, especially after [Dellavedova's] Game 6 against the Bulls, and now meeting Bogut in the Finals," said Hammond, who will be airing the games at the store. "There's only a few people here who believe the bulls--t that Delly plays dirty, but they're just Bulls, Hawks and Warriors fans."

This past season, a record eight Australians played in the NBA, with six this postseason. And this is the first time that Australians will face off against each other in the Finals, according to the NBA. In fact, Bogut and Dellavedova have attracted two of the country's largest channels, seven and nine, as well as Fox Sports Australia, to cover the Finals in the states.

Back in Cleveland, how big has Dellavedova gotten lately? On Monday night, maybe as many as 1,000 people came out to Summit Mall in suburban Akron to meet him.

While he won't be taking over for James in his own hometown, Dellavedova does share a similar do-it-all mentality, which could be the biggest X-factor for the Cavaliers in the Finals, starting Thursday night.

"Delly's the kind of guy that you can throw in any situation," said Cavaliers coach David Blatt, who started working with Dellavedova last summer in Vegas. "He's one of those kids that if his parents were to throw him into the water before he knew how to swim, he'd be doing the backstroke, the breaststroke and the crawl before any of us even figured out he was in there. So whatever we need him to do, he'll be ready to do."

Jared Zwerling covers the NBA for Bleacher Report. Follow him on Twitter and Instagram.