The Sixers and Celtics played an entertaining opening game of the first round playoff series. Here are observations from Boston’s 109-101 win in Game 1.

Right opening mindset for Embiid: With Ben Simmons out, the Sixers need Joel Embiid more than ever, and from the opening quarter Embiid was going to establish his dominance down low. The only time Embiid had problems was when he mishandled a pass or tried to take that extra dribble, but he had no problem establishing position on Daniel Theis.

Embiid was posting effectively and having no trouble scoring to begin the game. And the only time he took an outside shot in the first quarter was with the shot clock running, and he made a step-back three.

In the second quarter, Embiid only took two shots. That should never happen.

Embiid was more aggressive in the second half, but not to the degree he was in the first quarter.

Textbook play in the post:: The Sixers have been effective with Horford and Embiid playing a high-low game when both are on the court.

In this play, Horford is down low and Even when Embiid didn’t post up, he was the eventual beneficiary.

Horford drove to the basket and drew two defenders, including Embiid’s man Daniel Theis. Horford recognized Theis was out of position and hit Embiid, who emphatically finished matter.

Here is another example in the third quarter with Horford positing up Tatum.

Even though he missed the first shot, Horford scored on the follow. With Embiid out of the game, this is exactly what the Sixers needed.

Too many turnovers: The Sixers had seven first quarter turnovers compared to one by the Celtics, yet the Sixers led by one after the first 12 minutes. The Celtics needless to say didn’t take advantage of all the Sixers miscues. The Celtics should have had a comfortable lead with that disparity. The turnovers, in the second quarter would eventually cost the Sixers.

Sixers defensive play of the game: No surprise that Matisse Thybulle, shortly after he came in the game, made this gem against Tatum.

Despite being picked off the play by Theis, Thybulle fought off the pick and blocked the shot.

Tatum to the basket with authority: That block seemed to wake Tatum up. At times he can get too enamored with the three-point shot, but Tatum had a more aggressive mindset. He began driving to the basket and in turn, that bought him space to hit additional threes.

Tatum’s ability to read a play is among his greatest traits.

On the above play he gets a step on Tobias Harris and then waits as Theis seals off Embiid (although it could have been a moving pick). Still, Tatum wasn’t in a rush, took it at his pace and made the basket.

After Thybulle’s block of Tatum’s shot, the Celtics all-star continually had success taking the Sixers rookie off the dribble.

On this play, he takes Tobias Harris off the dribble and scores.

A few times it appeared as if Tatum was fouled on these journeys to the basket, but he didn’t get the calls.

Smart moves: Celtics guard Marcus Smart is among the top defensive players in the league and one thing he does so effectively is get his hands on a lot balls from the weakside. Almost any time that Embiid would get the ball in the post, Smart would get in the vicinity and swipe a ball. Embiid should not want to dribble too much with Smart anywhere in the vicinity.

Tobias leads the comeback: The Sixers trailed by as many as 11 points in the third quarter, but they got back in the game as Tobias Harris started getting aggressively offensively. The Sixers ended the third quarter with a 79-75 lead and Harris was one of the catalysts.

A late lift by Brown: Jaylen Brown gave the Celtics a major lift in the fourth quarter. Brown’s game is so versatile and he is an improved three-point shooter.