It's official, the Boston Celtics are through to the second round of the Eastern Conference playoffs. The Orlando Magic gave them some problems, specifically in how they impacted Boston's work on the perimeter. Yet, as the series wore on, Joe Mazzulla and his coaching staff found some adjustments that began negating Orlando's key skill.

With the New York Knicks losing to the Detroit Pistons last night, Boston will get some additional rest. The Knicks are back in action on Thursday, but if they drop game six, then great, more rest for the Celtics. And if we're being honest, the Celtics need all the rest they can get right now.

Another bonus of there being a slight gap between this series and the next is that it gives us the breathing room to dissect a few things and start looking ahead. It allows everyone to learn some lessons on what can be improved and what can be replicated.

I wanted to get in on that. So, today, we're looking at three lessons we've learned from Boston's opening playoff series.

#1 There's an ad(justment) for that

I'm probably showing my age here, but back when the first iPhone was released, specifically the iPhone 3G, there was a TV advert that sold the phone by asking a question, and the reply was, "There's an app for that."

As we worked through five full games of this series, I found myself chuckling at the thought of Joe Mazzulla, sitting in a coaches meeting, watching a possession break down on the perimeter and confidently declaring "there's an adjustment for that."

No matter what the Magic threw at the Celtics in terms of perimeter defense, Boston came right back with fresh new ideas. Most of the time, those ideas worked, too.

“You could just tell their experience showed,” Banchero said on Sunday. “They weren’t rattled at all."

Yesterday, we looked at how Mazzulla added a second screener into a staple action from Boston's playbook. And last week, we saw how the Celtics changed their positioning to remove perimeter defenders. Both of those deeper dives are into the type of adjustments we're talking about.

As a quick side note, I know that I like to use names of plays when doing those deep dives, please never think the names are important. I use them as a way for me to quickly recognize the actions on the floor. The only important aspect is why those plays did or didn't work.

Anyway...There were plenty more of those adjustments, too!

Mazzulla has proven himself adept at evolving throughout a series, especially when it comes to limiting a team's biggest strength while also attacking their weaknesses. We will need to see more of those tweaks moving forward, especially as the Knicks (assuming they eventually win their series) will post a totally different type of threat.

#2 The Celtics can win on the inside

When discussing the Celtics and their chances of success, shooting variance is always a topic of discussion. The Celtics like to let it fly from deep. They take and make a ridiculous amount of threes. However, there are times when shots simply don't fall. It's part of the game, after all.

Against the Magic, Boston's three-point attempts were particularly low, especially by their own standards.

• Game 1: 37 3-point attempts
• Game 2: 37 3-point attempts
• Game 3: 27 3-point attempts
• Game 4: 31 3-point attempts
• Game 5: 24 3-point attempts.

The Celtics' conversion rate was also below their usual standards.

• Game 1: 43.2%
• Game 2: 32.4%
• Game 3: 33.3%
• Game 4: 29%
• Game 5: 54.2%

Ok, so games 1 and 5 were solid in terms of conversion. Games two, three, and four left something to be desired.

Still, the Celtics won four of those five games. That means they found ways to win, even when shots weren't falling. Of course, that means more scoring was coming on the interior, both at the rim and in the mid-range.

Sometimes, being put into uncomfortable positions forces growth. And while the Celtics undoubtedly knew they could win a dogfight on the interior, being forced into doing so will only sharpen their execution. I lost count of the times we saw Kristaps Porzingis duck into a post-up, or Jayson Tatum going to work in the mid-post.

And, by the end of the series, even Sam Hauser and the bench mob were getting involved.

Orlando is one of the best perimeter defenses in the NBA – if not the best. Still, knowing that the Oklahoma City Thunder – another elite perimeter defense — could be waiting in the NBA Finals, I feel like this series was a great test of character and desire to win. And if you ask me, those are great lessons to learn right out of the gate.

#3 The Celtics might not stay 100% healthy

Boston's season has been littered with injury issues. We've rarely seen the starting five at full strength. So, when Jruey Holiday went down after game two, it wasn't too difficult for the Celtics to change course without hitting so much as a speed bump.

Obviously, the Celtics are better with Holiday in the rotation. They're better when everyone is healthy. I don't think that's breaking news. However, knowing that the current rotation is sorta banged up, and that there's a chance Holiday or someone else goes down for a few games, it's comforting that this year's Boston team has endured multiple stretches of short-handed basketball.

In truth, the Celtics were short-handed for most of the championship run, due to Porzingis' injury. This year, it could be Holiday who sits out segments of a series – although I hope that's not the case.

Looking back, maybe all those injury issues and different lineups, rotation combinations and substitution patterns throughout the season will end up being a core component in what could be another run toward a championship.

Final Thoughts

So, yeah—this series had its moments. The Magic threw a few punches, landed some, and made Boston work for it. But the Celtics responded like a veteran group with bigger goals in mind. They adjusted, they adapted, and they found different ways to win.

Now, with an opportunity to gain a little extra rest, the Celtics are in a good spot. Whether it’s the Knicks or a Game 7 miracle from Detroit (not holding my breath), Boston’s next challenge is coming. And if we’ve learned anything from this opening round, it’s that this team has layers, counters, and just enough grit to push through when things get messy.

Time to exhale.

Because in a few more days, we will all be holding our breath again.