It seems the Celtics have been trying to solve the mystery of their fourth-quarter disappearances for years, even before the Brad Stevens era began.
It was no surprise that just 2 minutes and 56 seconds into the fourth quarter on Friday night at TD Garden, the Celtics' once-formidable 17-point lead had been whittled to 9 by one of the NBA's best teams. Opposing teams not only see vulnerability in the Celtics in the final quarter but weakness.
They realize the Celtics have trouble executing in the final quarter, when the pace slows down and the Celtics are challenged to successfully run their halfcourt offense. It's no coincidence that teams suddenly step up their defensive intensity, as the Cavaliers did on Friday and Thunder on Wednesday.
The Celtics are making themselves easier to stop because they rely too heavily on the perimeter shot and don't get to the free throw line.
In eight fourth quarters this season — three of those victories — the Celtics are getting outscored, 29.1-24.5, while they are shooting 43.4 percent compared with 51.2 by opponents. What's more, in the past three games, two of those losses, the Celtics were outscored, 105-65, in the final quarter, including 38-20 Friday.
Stevens's biggest challenge over the next several weeks is devising a plan to improve down the stretch with a dominant post scorer besides undersized Jared Sullinger. The primary issue with a lack of fourth-quarter offense is a lack of free throw shooting.
For example, the bruising, physical Sullinger has just 18 free throw attempts this season in 245 minutes played. Reserve Tyler Zeller, who does nothing but run the floor and dart for the basket on fast breaks, has 15 attempts in 103 minutes. Kelly Olynyk, the team's No. 4 scorer, has also attempted only 18.
And Avery Bradley, while improving offensively as the season progresses, does not get to the free throw line. He is tied for 189th in the NBA in free throw attempts, among the likes of Ronnie Price, Wesley Johnson, and Shane Larkin.
Stevens understood that his team would be perimeter dominant from the start of training camp, and the plan was to use a faster pace to capitalize on the outside shooters and use ball movement to create open shots. But what happens when the pace slows, the Celtics' defense wears down and allows baskets, preventing them from breaking off missed baskets?
That is the next predicament for Stevens, figuring out how to make his team more productive in the final quarter while also improving the defense. It's all connected.
"I'm frustrated by it. I want to be better at it," Stevens said after Friday's game. "I thought our energy and togetherness and sustainability was much better [Friday]. When things went south, we came back. They went up by 3; we ended up tying the game. Jeff [Green] made a great hustle play to get the free throws.
"You know, if you turned on the TV last night you saw it in at least two games, maybe three — and that happens. You've got to play all 48. You've got to be great all 48 against this team. And it's not the same against everybody, but you still have to be on your 'A' game the whole time."
But it should have never come down the final minutes. The Celtics led by 19 points in the fourth quarter. They led by 18 in Chicago last Saturday before Aaron Brooks turned into Isiah Thomas circa 1988, and the Celtics were forced to use critical rebounds to secure the victory.
Rajon Rondo took full responsibility for botching the final play of the game against the Cavaliers by allowing the ball to roll up his arm, but he pointed to the defense as the issue in the fourth-quarter meltdowns.
"I just don't think we're sustaining our defensive intensity throughout the whole 48 minutes," he said. "I don't think we get comfortable. Teams are desperate. They're going to make shots, make plays. [The Cavaliers] got us on our heels and we were able to make consecutive stops. When we get stops, we're a great offensive team. When we get stagnant, our offense isn't as fluid as we'd like it to be, as far as how we did in the first three quarters."
Something happens when that quarter clock strikes four and the Celtics have to figure out ways to secure leads and avoid foul trouble. Defensively, they are making stars out of reserves such as Brooks and the Thunder's Anthony Morrow. In their haste to make a play, they are careless with the ball, such as Bradley's Rondo-like whip pass intended for Brandon Bass that skidded out of bounds. Or consecutive travel calls on Evan Turner and Sullinger when both moved their pivot feet to make a one-on-one move.
The Celtics need to calm down, run their base offense, and challenge officials to make foul calls instead of settling for contested jump shots. In that fourth quarter against Cleveland, the Celtics converted eight shots, committed seven turnovers, and attempted four free throws.
The Cavaliers: 10 made shots, 1 turnover, 17 free throws.
So their comeback wasn't such a mystery. The Cavaliers were the more aggressive and savvy team, and that is the difference between winning close games and losing them.
Gary Washburn can be reached at email@example.com.