The second-seeded Boston Celtics have shocked many and taken a 3-0 series lead on the Brooklyn Nets in the first round. Heading into the series, the seventh-seeded Nets were a popular upset pick thanks to the duo of Kevin Durant and Kyrie Irving. Now, those Nets are tasked with doing something no NBA team has ever done: coming back from down 3-0 to win an NBA playoff series.

The games have been close, as the Celtics average margin of victory has been just 4.7 points. In a win-or-go-home Game 4 for the Nets, it should be another close one. Let's take a look at our bold predictions for the Celtics in Game 4.

Celtics 3 Bold Predictions

3. Marcus Smart scores 20+

Marcus Smart has been known for his defensive abilities since he's gotten into the NBA, as evidenced by his recent Defensive Player of the Year award. Despite that, Smart has quietly become a very good secondary scorer for the Celtics. Jayson Tatum and Jaylen Brown are obviously expected to carry the scoring load on most nights, but Smart has shown he's capable. He's averaged over 12 points per game in three consecutive seasons now and his jumper is at least respected by his peers.

He's shot 33% from behind the arc the past two seasons now, as he struggled to break 31% in three of his first four NBA seasons. Smart's playmaking has taken a jump as well, as he averaged a career-high 5.9 assists per contest this year. Those improvements were on full display in the final play of Game 1, as Smart made a phenomenal pass to set up Tatum for the game-winner. In past years, the Oklahoma State product may have taken a shot upon catching Brown's pass. In the series, Smart is averaging over 15 points per game, yet is shooting just 28% from 3. The looks have been there, but he just hasn't capitalized. That will change in Game 4, as Smart will go for more than 20 points.

2. Kevin Durant continues to struggle

The Celtics have been able to do something that perhaps no team has: slow down Kevin Durant. Considered the best player in the world by many, Durant has simply looked flustered all series. Jayson Tatum has dominated the two's matchup, playing elite defense on Durant. In turn, Durant's aggression has regressed over the past two games. Durant had his worst performance at home in Game 3, scoring just 16 points on 11 shot attempts in 45 minutes. He got to the free throw line just twice after going 18-for-20 in Game 2.

The Celtics physical style of defense has presented problems for both Durant and Irving. That won't change just because the series is now 3-0. Durant's series numbers are down from the regular season in virtually every statistic. In three games, he's averaging just 22 points on 36.5% from the field and 5.7 turnovers. His true shooting percentage is down nearly 12% from the regular season. Holding him to 16 points won't happen again, but Kevin Durant will continue his series-long struggles in Game 4.

1. Celtics sweep

Last but not least, the Celtics will sweep the Nets. This may not seem that bold, but the Celtics finishing off the Nets in four games would still be surprising. Everyone is still waiting for Durant and co. to put up some sort of fight before going down. Additionally, Monday's Game 4 is still in Brooklyn at the Barclays Arena. The Nets open as two-point favorites over the Celtics, as Ben Simmons is expected to make his Nets debut. He's not played since the playoffs last season, so his effectiveness is to be determined.

With all of that being said, the Celtics have simply been the best team all series long. Nothing suggests that things will change, even if the Nets benefit from a Simmons return. The Celtics defense has disrupted the rhythm of the Nets offense all series long, Durant most specifically. That side of things will keep them in any game. Even when Tatum or Brown have struggled for spurts, the C's have manufactured enough offense to keep afloat.