Friday night's thriller between the Boston Celtics and the Cleveland Cavaliers might go down as one of the most exciting games of the regular season; it was a fast-paced match with sensational offense, spectacular individual plays, and an incredible comeback by Cleveland.

But trailing 122-121, with a chance to win the game in the final seconds, Rajon Rondo bobbled the ball away and didn't even attempt a shot as the clock ran out.

A Rondo game-winner could've added an exclamation point to an otherwise extraordinary game, but his fumble instead left this game without any punctuation at all.

The anti-climatic ending just left a sour taste in the mouths of Celtics fans.

One elderly fan sitting behind me screamed, "Brad Stevens is a terrible coach! What a horrible play! He needs to be fired!" He must've been snoozing away during the first 47 minutes and 53 seconds of the game, and missed out on the Celtics going toe-to-toe with arguably the most talented team in the NBA.

On social media, some Celtics fans were calling Rondo a certified choke artist. They apparently never watched any of Rondo's heroic playoff performances.

In reality, Boston didn't lose this game on the final possession. They lost it throughout the entire fourth quarter due to porous execution. The last play was really just a microcosm of the final 12 minutes.

But since there is so much focus on Rajon Rondo's missed opportunity on the final play, let's break down what went wrong anyway.

"I lost the ball," Rondo told reporters when asked to describe what happened on the final possession. "Give them credit, they played good defense. I lost the ball and didn't get the shot off in time."

With a handful of New England Patriots players in the building, Boston's star point guard did his best Bill Belichick impersonation with such a succinct response, but he's 100 percent correct. When it comes to the result, Rondo really just did lose the ball. It's that simple. But there was a lot more to the process of the play.

"We had a couple of different options," Brad Stevens said when asked to explain the last play. "We had Jeff over the top; I'd have to look at the film to see if he had LeBron sealed for a lob, which obviously would've been a risky pass. But we had just thrown it to Jared and then we just had a simple swing to Rondo and our desire was to reject the screen."

Here's what Stevens is describing:

Even before the ball was inbounded, there were two primary actions occurring. Avery Bradley set a cross screen for Jeff Green, and the inbounder, Kelly Olynyk, pump-faked an alley-oop.

As Stevens alluded to, this would've been a difficult pass, so Olynyk just inbounded the ball to Sullinger instead. However, Olynyk's pump-fake could've drawn Sullinger's man, Shawn Marion, down into the paint, which would've freed him for an open shot.

After watching the film, Stevens will find that the lob wasn't there, because LeBron James plowed through Bradley's screen. Olynyk correctly inbounded the ball to Sullinger, who then swung it over to Rondo with 5.8 seconds left on the clock.

The execution is terrible here in a number of different ways. First, it takes 1.7 seconds for Rondo and Sullinger to use the screen, which is an eternity at this point of the game.

Secondly, Rondo was supposed to reject the screen, as Stevens said. What was supposed to happen was Rondo penetration, which would've forced LeBron James to help off of Jeff Green. Rondo would've had the option for a layup or a kick out to an open Green.

It's possible that in the moment Rondo made the decision to use the screen, knowing Cleveland would switch, because what happened next was almost too good to be true for Boston. Still, the fact it took 1.7 seconds for Rondo and Sullinger to even initiate the action eliminated the option of driving to the rim.

With 1.8 seconds remaining in the game, Sullinger had perfect inside positioning for Rondo to make an over-the-top pass for a quick layup. There is absolutely no way that Joe Harris could've stopped the 260-plus pound Sullinger.

But Rondo bobbled the ball, which removed any chance at all of anything positive. Kelly Olynyk and Avery Bradley were being used purely as floor-spacers, so Rondo in isolation, Sullinger over-the-top, or Green floating to the wing, were the only three options at this point.

Some critics will blame Stevens for even calling the play for Rondo, who was just 1-for-7 on shot attempts outside of the restricted area, but no matter what happened earlier in the night, he is the team's best playmaker and shot creator. Stevens made the right decision in utilizing his best weapon, and the play had multiple options, all of which were well designed, but the execution wasn't as crisp as it needed to be.

Had any of the options worked out the way they were drawn up, the Boston Celtics could've been walking out of TD Garden with a victory. But as is the case with many young teams, poor execution down the stretch was their downfall. Boston needs to find out how to close games, or else they will continue to suffer many heartbreaking losses over the course of the season.

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