My prediction was totally wrong. At the beginning of the season, I kept my expectations low. The Boston Celtics would play most of the season without All-Star Jayson Tatum, there was uncertainty surrounding how All-Star teammate Jaylen Brown would take on the role as leader of the team and head coach Joe Mazzulla would be tested with a lineup that lost a few starters in the offseason.

“Even if [Tatum] does feel 100% come March or April, the Celtics have no need to put him back on the parquet as they aren’t considered contenders this year,” I wrote in October.

Now, Tatum is back and the Celtics are the No. 2 seed in the Eastern Conference and are widely considered championship contenders. Sometimes it pays to have low expectations, as in this case when Celtics fans are rewarded with a team that is creating the same buzz and excitement it has for the past few years.

So what caused the Celtics to go from play-in hopefuls to trophy chasers? 

First, there’s credit due to Mazzulla. His coaching expertise was put to the test this season after losing three big men in Kristaps Porziņģis, Al Horford and Luke Kornet. The Celtics lost height, rebounding and 3-point shooting, and Porziņģis and Horford have now teamed up on the Golden State Warriors, another 3-point shooting offense.

But their replacements have not disappointed. Starting center Nemias Queta (10.2 points per game, or ppg, 8.4 rebounds, or reb, 1.3 blocks, 25.3 minutes) is arguably one of the most improved players in the entire league from last year, and offseason addition center Luka Garza (8.1 ppg, 4.1 reb, 16.2 minutes) has fit the Celtics’ scheme close to perfection. The team also added center Nikola Vučević (9.7 ppg, 6.6 reb, 2.0 assists) in a trade, giving up guard Anfernee Simons. Mazzulla has found the right combination of guys to put on the court at a time for optimal usage.

One of the best examples of “Mazzulla ball” that went beyond defensive pressure and long-range shooting was in the final minutes of a thriller against the Brooklyn Nets Jan. 23. 

With 7.9 seconds remaining in the overtime period, the Celtics trailed 117-112 and were desperate for a basket, with both key big men in Garza and Queta fouled out. G League forward Amari Williams checked into the game for only the eighth time all season and immediately made an impact.

Mazzulla designed an inbounds play where forward Sam Hauser threw the ball from one end of the court to the free throw line of the other and Williams quickly caught and dished it to guard Payton Pritchard, who buried a three to cut the lead to two. It was timely and efficient, and after a missed free throw on two tries by the Nets, the Celtics used a timeout down three with 2.5 seconds remaining; enough time to reach into the playbook and draw something up.

The huddle breaks, guard Baylor Scheierman gets set to inbound when Mazzulla channels his inner quarterback and calls an audible. He subs out Williams for rookie guard Hugo González at the last second. Players get into formation, and the ref blows the whistle to signal the start of play. 

Teammates intersect like strings of yarn as the needle finds González on the near side of the court with no defenders around him. He launches it quickly from distance and punctures the net with a satisfying swish.

The Celtics then went on to win 130-126 in double overtime. It was a prime example of the pressure surrounding the team with a changing roster and key players out during clutch time. 

“To be able to sit through the entire game and be ready and execute some of the plays that we’ve gone over in practice, it’s a credit to [González] and the coaching staff for the guys that work with him, getting them ready to go,” Mazzulla said postgame. The rookie González and the “Stay Ready Group” will be a large factor in the playoffs.

The team’s defense is still one of the best in the NBA. This season, they allowed the least opponent points per game in the league with 107.2 points allowed each contest. My defensive player of the year prediction in guard Derrick White lived up to expectations, averaging 1.1 steals and 1.3 blocks per game, leading the team in “stocks” — steals and blocks combined. Pritchard is the easy sixth man with my prediction underestimating his facilitating, as he averaged 5.2 assists per game.

So with Tatum back and looking like his regular self, Brown in league MVP conversations while averaging 28.7 ppg, 6.9 rebounds and 5.1 assists, and Mazzulla’s coaching, how will this all add up to an NBA Finals run? 

The No. 2 seed Celtics (56-26) will face the No. 7 seed Philadelphia 76ers (45-37) in the first round of the playoffs. Philly is without star center Joel Embiid due to appendicitis and his timeline to return is uncertain. Embiid has only played in 38 games this season, and the Sixers were 24-14 when he was available, and 21-23 without him (excluding their play-in win over the Orlando Magic). 

Boston will have home court advantage until the chance they face the top-seed Detroit Pistons — who I thought would have been in a different position, as I predicted the Cleveland Cavaliers to emerge as the best in the East. You win some, you lose some.

The Celtics can’t get too cocky though. In four matchups between the two teams this season, they each won two, with three games decided by two points or less. The 76ers have a high volume offense paired with a strong defense of their own that ranks top-five in steals and blocks per game. It’ll be a tough task to contain Tyrese Maxey, who has averaged 30 points and nearly nine assists in four games against the Celtics this year.

I predict a 4-1 series win for Boston. They have Tatum back who draws the focus away from other star players who can easily use that to their advantage. Bracing for any sudden injuries, the Celtics’ road to the Finals will be difficult nonetheless with the talent in the Eastern Conference. Last year, I predicted a championship appearance, but that dream was cut short when Tatum went down with his Achilles injury. 

I don’t want to get my hopes up, and there’s certainly a lot of buzz around this Cinderella run that the Celtics are having, but here we are again, looking to raise another banner.