After the Indiana Pacers put together the best shooting performance in NBA playoff history to advance to the Eastern Conference finals, Tyrese Haliburton wanted to set the record straight on his team's status as the surprise of the 2024 playoffs.

"It's no fluke," the All-Star guard said Sunday after Indiana captured Game 7 at Madison Square Garden. "We expect this from our group, and then once we added [Pascal Siakam], we knew that we could really take off.

"It doesn't really matter what anyone thinks except the people in our travel party. Because I don't think anyone here picked the Pacers to win the series."

After their Game 7 win, things won't get any easier for the underdog Pacers, who before this season hadn't won a playoff series since reaching the conference finals in 2014. The next challenge: taking down the 64-win Boston Celtics, who are in the East finals for the sixth time in eight seasons.

Ahead of Tuesday's Game 1 (8 p.m. ET on ESPN and ESPN2), here's a look at the factors that will determine which contender will advance to next month's NBA Finals.

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How the Celtics and Pacers got here

Boston has comfortably run through the opening two rounds of the playoffs. The Celtics dispatched the Miami Heat in five games as Jimmy Butler missed the series with a knee injury, and only a historic shooting performance by Miami in Game 2 prevented a sweep.

The Celtics coughed up another Game 2 loss at home to Cleveland, but Donovan Mitchell's exit with a calf injury after Game 3 turned that series into another five-game triumph.

Indiana, meanwhile, has reached this point with a breakneck offensive pace led by Haliburton. But there is so much more to the league's second-rated offense. Siakam attacks relentlessly and gives the young club some much-needed playoff experience at the top of the rotation, while backup point guard T.J. McConnell is integral to arguably the NBA's best bench because of his underrated midrange jumper and his ability to hound opposing players for 94 feet.

Pundits will inevitably point to Indiana's first two playoff opponents and cite injuries to the Milwaukee Bucks' Giannis Antetokounmpo and Damian Lillard and the New York Knicks' Julius Randle and OG Anunoby, among others. But the Pacers have enough young talent -- especially on offense -- to become a perennial player in the East's playoff picture.

Porzingis' availability is Boston's biggest unknown

The 7-foot-3 center, acquired by the Celtics during the offseason to give them a different look against switching defenses in the playoffs, has been sidelined with a calf injury since Game 5 against Miami. He has slowly begun ramping up his activity over the past couple of weeks but is expected to miss at least the first two games of this series, sources told ESPN's Adrian Wojnarowski on Friday.

Porzingis is an elite rim-protector and 3-point shooter who recorded career highs in field goal percentage (52%) and effective field goal percentage (59%) this season and allowed just 44.3% shooting in the paint, second best among players to contest at least 300 shots this season, according to Second Spectrum tracking data.

Can Indiana's defense afford to double Jayson Tatum or Jaylen Brown?

In not seeing the Bucks or Knicks at full strength, Indiana was generally able to avoid having to defend multiple stars at once. Because of that, the Pacers were able to throw multiple defenders at Knicks guard Jalen Brunson, just as they were able to throw swarms at Damian Lillard in the first round.

The question now is whether Indiana can defend the high-powered Celtics well enough. If the Pacers try single coverage against Boston's superstar wings, the Celtics could dominate the free throw battle. No team in the league sent opponents to the line at a higher rate than Indiana this season.

Doubling could prove just as risky. The Celtics took and hit more 3-pointers than any other team. However, the Pacers surrendered fewer attempts and makes than any other team in the league during the regular season.

Matchup to watch: Haliburton vs. Boston's stingy backcourt

To have a chance in this series, Indiana will need elite offensive production from its star point guard against arguably the league's best defensive backcourt in Jrue Holiday and Derrick White.

The Pacers got such a performance during their in-season tournament victory against Boston on Dec. 4, when Haliburton had 26 points with five 3-pointers, 13 assists and 10 rebounds to advance to the IST semifinals in Las Vegas.

Holiday and White, however, are both long and rangy enough to give Haliburton plenty of trouble throughout the series. Boston's duo is coming off a Game 5 victory in which it helped hold Cleveland guards Darius Garland and Max Strus to a combined 23 points on 7-for-27 shooting.

Indiana's turbocharged offense is built around the scoring and playmaking of Haliburton. Holiday and White present the toughest challenge yet.

Series wild card: The rebounding battle

If the Pacers' defense is spread thin -- because Indiana opts to double-team or due to Boston's ability to space the floor with shooters -- the question of rebounding could be critical, just as it was in the conference semifinals between New York and Indiana.

In Game 5 of that series, during which the Knicks started 6-1 guard Miles McBride over 6-8 forward Precious Achiuwa, Indiana struggled defending Brunson. When the Pacers sprinted at him, he dumped the ball to McBride, who served as a screener and release valve on offense.

Boston will have similar counters, ones that are potentially more efficient than New York's. The Pacers, who struggled mightily at times to keep the Knicks off the offensive glass, might have that problem against the Celtics, too. Indiana ranked 26th in defensive rebound rate during the regular season. By halftime of that Game 5, the Knicks had more offensive rebounds than the Pacers had total rebounds.

Stat that could define the series: Points!

The Celtics and Pacers ranked first and second in offensive efficiency this season, but the East finalists got there in dramatically different ways: Boston led the NBA in made 3-pointers, while Indiana led the league in paint points.

This is the sixth playoff series since 1998 to feature the top team in made 3s against the top team in paint points, and it's the first in a conference finals or later since the 2000 NBA Finals between the Pacers and Los Angeles Lakers. In the past five such meetings, the team that led the league in paint points won three of them.

ESPN Stats & Information's Matt Williams contributed to this story.