NBA playoffs: You have questions about the Celtics? We have all the answers.

The Celtics are ready to start the NBA playoffs and chase the championship that eluded them last season. So let’s take some questions. We’ll start with the man in the back wearing the “In Brad I trust” hoodie.

It’s about time. So, the Celtics had some success during the regular season. But championships are won with defense. This team just doesn’t have last year’s tenacity at that end.

The Celtics defense was not great at the start of the season. But that changed. The return of Robert Williams after a 29-game absence helped, as did Derrick White’s emergence as a likely All-Defensive team selection.

The Celtics actually finished the year with the NBA’s second-ranked defense, allowing 110.6 points per 100 possessions. They also had the No. 2 offense. No other team is in the top six in both. Last year’s squad, by comparison, had the top-ranked defense and the eighth-ranked offense.

Can Joe Mazzulla really be a championship coach this quickly, though? I heard his only head coaching experience before this season came in middle school.

It actually was in college, at Division 2 Fairmont State. But he has been with the Celtics since 2019 and learned under Brad Stevens and Ime Udoka. He also just guided the Celtics to 57 wins, more than Stevens or Udoka ever did. He seems ready.

Mazzulla stressed this week that success will come down to the simplest details, such as grabbing a rebound and stopping an opponent’s fast-break chances, not deciding when to give Jayson Tatum a rest. And let’s be honest, a coach never has to take free throws with his team trailing by a point with one second left.

Yeah, but he doesn’t even use timeouts!

That’s not really a thing anymore.

The Eastern Conference is so much better. Can you give me a reason to believe Boston can beat the Hawks, 76ers, and Bucks?

This season, they went a combined 8-2 against those teams, which are now Boston’s most likely opponents over the first three rounds. The only losses were an overtime setback in Milwaukee in which almost all of the Celtics’ top players sat out, and a 2-point loss to the 76ers without Jaylen Brown and Robert Williams.

The Hawks simply don’t have the defenders to stop the Celtics. The 76ers rely too heavily on Joel Embiid. A Bucks series could go either way, but the Celtics have been able to expose older, slower defenders such as Joe Ingles, Khris Middleton, and Jae Crowder.

Don’t you think this little Q&A is a bit optimistic? There must be some concerns, you homer.

Well, the biggest and most obvious one is health. Last year, Williams missed the start of the playoffs and was hobbled when he returned. The year before that, Brown was sidelined. If you want to go way back and keep hurting, there were the Kyrie Irving and Isaiah Thomas injuries.

Dude, please don’t mention Kyrie here. Come on.

Anyway, health is important. The Celtics should have little trouble getting past the Hawks while missing a key piece or two, and probably could withstand the absence of someone other than Jayson Tatum or Brown against the 76ers. But after that, it gets tricky.

But health is important for everyone. One more concern, please.

Tatum shot a career-low 35 percent from the 3-point line this season, and just 32.8 percent after being named MVP of the All-Star Game in February. Don’t think that’s important? Well, the Celtics are 17-1 this season when Tatum shoots 45 percent or better.

More than most other superstars, Tatum’s long-range success seems to be tied to his confidence. The Celtics need to do all they can to get him good, clean looks to find an early rhythm.

Beyond Tatum and Brown, who is the X-factor?

The Celtics have been extremely cautious with Williams, but they feel good about ramping up his workload. He said his body feels good.

The Celtics have had success with Williams on the court, outscoring opponents by 11.4 points per 100 possessions, the best net rating on the team. That stat is even more impressive when one considers that Williams missed all of the team’s 21-5 start.

Still, Williams has not had as many above-the-rim flashes of dominance at either end of the court. His points, assists, steals, and blocks per 100 possessions are down a bit from last year, and his turnovers are slightly up. Mazzulla has been begging Williams to look to score more, and Williams insists that the message has been received.

I’ve never been to a Celtics game, but will I fit in if I just reuse some of my St. Patrick’s Day stuff?

That’s probably fine.

What will the closing lineup look like?

Tatum and Brown will always be in, but after that, plenty could depend on matchups, with Al Horford, Williams, Marcus Smart, White, and Malcolm Brogdon getting consideration. Mazzulla took some criticism during the second half of the year for keeping White on the bench late in some close games, but it appears the coach is ready to lean on White when it counts.

The Celtics have nine lineups that have played at least 50 minutes together this season. White is part of five of them, and they happen to own the five best net ratings in the group.

Sam Hauser (right) could make an impact off the bench in the playoffs.Matthew J. Lee/Globe Staff

The bench guys have all been pretty good when they actually get chances. Do you see any of them contributing in the playoffs?

The guess here is White remains in the starting lineup, with Brogdon and Williams having substantial roles. Grant Williams probably will get the first crack at being the eighth man, but it was an up-and-down season for him.

After that, Blake Griffin probably earned a chance with his hustle and effort plays, and Payton Pritchard is always ready to bring a jolt of energy. But Sam Hauser might be best positioned to be an unlikely postseason hero in a game or two.

Hauser shook off a midseason slump and finished the year shooting 41.8 percent from the 3-point line. Opposing offenses relentlessly attacked Hauser this year, but he actually finished the season with a league-leading 106.4 defensive rating.

That stat is wonky, since the other four players on the floor play a role. And Hauser is certainly no lockdown defender. But it’s probably evidence that teams go so out of their way to exploit him that they abandon their traditional offensive scheme, hurting its flow.

You have questions about the Celtics? We have all the answers.

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