Too many open threes

Boston shot just 4 of 18 from three-point range in the first half. While the Celtics missed several open shots, many others were also contested. That wasn't the case in the second half. Boston had several open looks and cashed in, getting back in the game by shooting 6 of 10 from beyond the arc in the third quarter, turning a 9-point halftime deficit to a six-point lead entering the fourth. This pattern continued in the fourth quarter.  It might be a sign of the Sixers youth, but they failed to lock down defensively after a strong first half and paid for it. Boston not only got several open threes but was also driving to the basket freely. The Celtics got back in the game with a strong second half showing by rookie Jayson Tatum, who was held to two points in the first half but finished with 16. In addition, the Sixers lost concentration on offense. After only two turnovers in the first quarter, they had 17 over the final three.

More post-ups needed from Embiid

There were times when Joel Embiid had 6-foot-9 rookie Daniel Theis on him and he wasn't trying to post up down low. Too many times Embiid worked outside, settling for a jumper when he could have destroyed Theis and the other Celtics defenders inside. Embiid finished with 15 points, but shot 6 of 17 from the field and 1 of 5 from beyond the arc. And a stat that showed he wasn't parked down low – Embiid failed to get a single offensive rebound.

Redick’s strong start couldn’t be maintained

J.J. Redick was the epitome of efficiency in the first half, with 18 points on just eight shots. Redick is among the best players in the NBA in moving without the ball and he had several open looks that he knocked down, scoring 13 points on 3 of 4 three-pointers for beyond the arc in the first quarter. Things slowed down a little for Redick when Boston put its best defender Marcus Smart on him, but Redick still was able to get open, often running off double screens. The Celtics should actually consider starting Smart against the Sixers, so Redick doesn't begin games on a tear. Smart often seems like a liability on offense, but he is a strong on-the-ball defender who brings a physical presence. Redick was able to help the Sixers jump out to a 22-point lead. He had 18 points at halftime but only four in the second half, showing that the Celtics made the adjustment of not allowing him much open space.

Heart of the Celtics

One of the most underrated players in the NBA is Celtics forward-center Al Horford. It might be hard to call a four-time all-star underrated, but Horford's fundamentally sound, but less than flashy game, isn't one that often generates headlines. Yet he showed his depth as a defender by starting out on Ben Simmons and later defending Embiid. Horford more than held his own on both players. Simmons quickness and Embiid's strength, would give any defender fits, but Horford did a solid job. He finished with a workmanlike 13 points, 8 rebounds and 7 assists and was a plus 32.

Credible job by McConnell

T.J McConnell needed to take the ball to the hoop at end of the third quarter, with Terry Rozier on him, he fed the ball back to Embiid, who didn't get his dunk off until after time in the quarter expired. Those type of mistakes cost the Sixers. That said, McConnell had another effective game penetrating. In two instances during the first half, he hit two pull-up jumpers within eight feet, showing that a player doesn't always have to go all the way to the hoop to score. He finished with 12 points, five assists and one turnover.