It all comes down to one game. With a 2018 NBA Finals berth on the line, the Boston Celtics play host the Cleveland Cavaliers in Game 7 on Sunday at 8:30 p.m. ET. Boston opened as a 2.5-point favorite. The Over-Under, or total number of points Vegas thinks will be scored, has ticked down to 199.5 from an opening of 201.5.

Before picking either side in the 2018 NBA Playoffs, you need to read what SportsLine senior analyst Larry Hartstein has to say. Hartstein is on a phenomenal 8-2 run on spread picks involving the Cavaliers and 21-12 with all NBA teams this postseason.

Now, Hartstein has examined every matchup, every player and every trend for Game 7 and locked in his pick. He knows the line is way off and says one team "comfortably" covers the spread. He's sharing why, and which team to back, over at SportsLine. 

Hartstein believes the absence of Kevin Love due to a concussion will stymie the Cavaliers, but won't be a mortal wound. He also has his eye on the Celtics' 10-0 record at TD Garden in the 2018 NBA Playoffs and is aware Cleveland has seized important games on the road, including two at top-seeded Toronto.

With Love out, expect the Cavaliers to play with a smaller, yet quicker lineup. Guard George Hill netted a quiet 20 points in Game 6 on 7-of-12 shooting. With LeBron James expected to be under duress every time he touches the ball, it's vital for Hill to hit his mid-range jumpers.

Just as important will be Kyle Korver's ability to knock down three-pointers. He's 12 for 22 from beyond the arc during the past five games, good for a 55 percent clip, but he's passed up open looks the past two games. Korver needs to play more selfishly and let his long-range shots fly.

As they've done all postseason, the Celtics can cover the spread by feeding off the intensity of the Boston crowd. The Celts are perfect at home this postseason and their average margin of victory has been over 11 points.

Jaylen Brown and Jayson Tatum have been clutch this postseason and they'll be called on to produce yet again. Their speed has given the Cavs fits this series, and their ability to drive to the hoop and kick out to the open man has been unparalleled. 

So which side of Cavaliers vs. Celtics do you need to be all over? Visit SportsLine now to see the bold point-spread pick by Hartstein, who has nailed 80 percent of his most recent spread picks involving the Cavaliers.