3 in the Key: Boston Celtics endure fourth quarter catastrophe, lose to Cleveland Cavaliers

Let's be blunt: the Boston Celtics have been a dreadful team in fourth quarter this season. Anyone who has watched them blow countless leads already knows that, and Brad Stevens does too. After last night's agonizing defeat to the Cleveland Cavaliers, Stevens was asked about his team's tendency to let leads slip away.

"I'm frustrated by it. I want to be better at it. I thought our energy and togetherness and sustainability was better tonight," Stevens somberly explained. "But you have to play all 48. It's not the same against everybody, but you still have to be on your A-game the whole time."

In today's edition of 3 in the Key, we're taking a look at how Boston is struggling late in games and how they should make adjustments:

Boston's defense dissipates late in games

Boston has been close to their A-game for the first three quarters of games this season. During that timeframe, they rank fifth in the NBA with a 109.2 offensive rating, though they are 21st with a 106.0 defensive rating.

However, looking solely at the fourth quarter, the Celtics see their efficiency fall off a cliff. In the fourth quarter, Boston ranks 16th with a 103.8 offensive rating and 30th with a 121.4 defensive rating.

Yes, you're reading that correctly, they are the worst defensive team in fourth quarter in the NBA. This -17.6 points per 100 possessions differential is 28th in the league, only above the struggling Pistons and 76ers.

Boston's dips in both offensive and defensive efficiency go hand in hand. They are letting their offensive struggles manifest on the defensive end, which can't happen against any team, never mind the Cavaliers.

Turnovers suddenly become an issue in the fourth

Boston led by 19-points early in the fourth quarter, but then the game changed after a chunk of stale positions. Players were holding the ball longer and generally becoming more cautious. While this isn't uncommon even among playoff-tested teams, those teams typically work through specific matchups or "go to the well" with their superstars carrying the late game load.

Even the San Antonio Spurs tend to concentrate their plays towards their "go-to" players, running the sets and actions that have the greatest chance of success in that specific game using that game's specific "stars of the night."

Since Boston struggles to find offense late in games, they are turning the ball over at an increasingly high rate. In the first three quarters, per 100 possessions, they rank second in assists and seventh in turnovers, for a sensational 1.99 assist-to-turnover ratio, ranking second. But in the final frame, they're 24th with 18 turnovers per 100 possessions.

This drop in production is incredible. They go from having the second best assist-to-turnover ratio to the 13th, which is the third largest differential in the league, behind only New Orleans and Miami.

Boston hasn't fully identified how to force other teams to adjust to them when the game slows down, not surprising this early in their collective experience, but they are exacerbating the issues by executing poorly and by allowing that to carry over to the defensive side of the ball.

The Celtics would probably have a couple more wins if they minimized at least one of these major issues, but this self-inflicting pain is happening on both ends of the floor.

Boston must ride the wave of whatever's working

The players and coaching staff need to do a better job of identifying what's working and just keep feeding it. For example, Oklahoma City did that against Boston by continuously running middle pick-and-rolls, resulting in open Anthony Morrow three-pointers, and so did the Dallas Mavericks, who seemingly scored at will in the pick-and-roll by exposing the Celtics' horrid help defense.

You don't just go away from what's working, because you're doing the other team a favor if you do. Kelly Olynyk played for 31 minutes last night and was on fire, hitting from everywhere on the court for his first 24 minutes, shooting 8-for-12 for 21 points. In just the first six minutes of the third quarter, he had 10 points on a perfect 3-for-3 shooting.

But in Olynyk's last seven minutes of action, he shot the ball only once, which is absolutely inexcusable. After reviewing the film, it doesn't appear that Cleveland adjusted to Olynyk, by overplaying him or sticking to him on drives; Boston was simply not running any offense through him. That needs to change, whether it's Olynyk or any other player who is red hot.

"One point not good enough," Stevens said he told his team after the game. "It is what it is. There's no moral victories, we can't talk about learning, we just have to get better and do it. That's where we all are."

Stevens is right; there are no moral victories, but they do have to talk about learning, and they have to work on their issues.

Each and every game Boston has blatantly avoided a matchup that showed signs of life, instead opting to run their stock motion-offense. The evenness of the roster has major benefits, but if a player is exploiting the opponent, you mustn't avoid him.

"We can't get frustrated with it and lose sight of the fact that we're eight games in and not 70 games in," Stevens later explained. "The good news is that there's a belief growing, but it has to be rounded out."

Boston went 12 rounds with an NBA Finals contender and there is nothing to be ashamed of in that, but when they had an opportunity to fire a knockout blow, they just leaned against the ropes.

If there's one thing to take away from last night, it's that this Boston Celtics team just needs to throw the haymaker when they have a chance.

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