The Boston Celtics are here, facing elimination from the NBA Finals, because they failed to execute their offense for a prolonged stretch of their biggest game of the season, and they are here, with an opportunity to force a Game 7, because they twice previously responded to the same failures in even bigger games.

The Celtics have completely malfunctioned at the end of a pivotal playoff game on three occasions, but they take a 3-0 record in elimination games into another one in Game 6 against the Golden State Warriors.

How has Boston melted down? And what can we take from the ensuing victories in Games 6 and 7 against the Milwaukee Bucks in the East semifinals and Game 7 against the Miami Heat in the conference finals?

Game 5: Milwaukee Bucks 110, Boston Celtics 107

Boston led the defending champions in the fourth quarter of a home Game 5 in the conference semifinals, 98-87, needing to survive the final 8:15 for a 3-2 series lead. The Bucks proceeded to outscore the Celtics 23-9 down the stretch and pushed them to the brink. Boston's offense over those final 17 possessions:

• Four turnovers (leading to six Milwaukee points)

• Three points on six isolation jump shots (Jaylen Brown gets his man to bite on a shot fake and makes 1 of 2 free throws, and a defensive miscommunication gives Jayson Tatum a clean look from 18 feet)

• Two points on four drives to the basket (three missed layups and a successful trip to the line)

• Two points on one catch-and-shoot opportunity (Al Horford finds Tatum for an 18-foot fallaway to beat the shot clock, Boston's lone assist in the final eight minutes of a game it lost by a single possession)

• Two points on one put-back dunk (Horford muscled home an errant Brown 22-footer)

• Nothing but a block on one cut to the basket (Boston's only other would-be assist in eight minutes)

It is hard to score when you turn the ball over on a quarter of your possessions and attempt as many isolated jumpers — the worst shot in basketball — as you do combined drives to the basket and passes into a shot. Getting two of your five layups blocked and not making the other three also does not help.

Five of Boston's last 17 possessions ended in points, and Milwaukee scored one point against the Celtics' set defense — a Giannis Antetokounmpo free throw off a questionable call. Meanwhile, the Bucks scored nine second-chance points, six points off turnovers, five off missed field goals and two from a take foul.

Game 6: Miami Heat 111, Boston Celtics 103

The Celtics led the conference's 2020 champions 97-94 in the fourth quarter of a home Game 6 in the East finals, and only 4:43 stood between them and their meeting with the Warriors. The Heat beat Boston 17-6 in that span to force a road Game 7 in Miami. The Celtics' offense on their final 12 possessions:

• Two turnovers (leading to two Miami points)

• Four three throws on six attempts from three non-shooting bonus fouls

• Two points on one drive to the basket

• Nothing on three isolation 3-pointers

• Nothing on three catch-and-shoot 3s (Boston's only assist opportunities in five minutes)

Boston's only attempt at the rim — and only field goal on 12 possessions — came when Miami's defense broke down off a long offensive rebound. The three catch-and-shoot 3-point attempts from Horford, Derrick White and Marcus Smart are better than the one the Celtics created in the final eight minutes of Game 5 against the Bucks, but if those are not falling, Boston manufactured little else of value on the home stretch.

Four of Boston's last 12 possessions ended in a total of six points. Miami managed five points on four ensuing possessions against a set defense — Kyle Lowry's contested 25-foot 3-pointer and Jimmy Butler's contested 20-foot turnaround jumper, both in the last five seconds of the shot clock. The Heat turned Boston's six misses into six points, two turnovers into two points and two take fouls into four free throws.

Game 5: Golden State Warriors 104, Boston Celtics 94

Boston led the three-time champions 71-67 with 1:38 remaining in the third quarter of a road Game 5 in the NBA Finals. From that point to the 3:42 mark of the fourth quarter, when the game was all but decided, the Warriors outscored the Celtics 26-8 to take a 3-2 series lead. Boston's 20 offensive possessions in that run:

• Four turnovers

• 10 points on eight drives to the basket (2-5 FG, 4-7 FT)

• Nothing on six isolation jump shots (three 3-pointers and three attempts inside the arc)

• Nothing on two catch-and-shoot 3-pointers (Boston's only real assist opportunities in 10 minutes)

The Celtics' eight drives to the basket were successful, even if two more of their layups were blocked, and their two passes into shots (on 20 possessions) produced clean looks, even if both resulted in bad misses.

Boston's inefficiencies on offense punctured holes its defense. Golden State scored 15 points off missed field goals and five from turnovers, plus a technical free throw. Only five of their 26 points in a 10-minute span came from the four Celtics possessions that ended in points — a Jordan Poole 3-pointer when the defense fell asleep and an Andrew Wiggins layup through two defenders who offered minimal challenge.

Melting down and icing up

In the aggregate, the Celtics scored 23 points (6-31 FG, 0-11 3P, 11-17 FT) on 49 possessions in almost 23 horrendous minutes against opponents looking for their third win in a best-of-seven series. That is 46.9 points per 100 possessions — or less less than half of their 110.8 offensive rating throughout the playoffs.

The defenses of the Bucks, Heat and Warriors play a role in those numbers, blocking the Celtics' only cut to the basket and three of their 13 driving layup attempts, but Boston's failures are largely self-inflicted. The Celtics committed 10 turnovers and scored three points on 15 isolation jumpers (1-14 FG, 0-6 3P, 1-2 FT) in half a game's worth of total work, meaning more than half of their possessions ended with someone either coughing the ball up to the other team or dribbling into a contested shot as his teammates idly watched.

The Celtics finished with a single assist on six made field goals (and seven assist opportunities on 31 field-goal attempts) in crucial stretches of three winnable games, and their offensive rating would have been worse (41.3) if not for three trips to the free-throw line on non-shooting fouls when they were in the bonus. The percentage of Boston's isolation possessions rose from less than 9% throughout the regular season and the rest of the playoffs to north of 30% during these offensive meltdowns in high-pressure situations.

The only thing that has worked for the Celtics when their offense stagnates is driving to the basket. Still, they only scored 12 points (3-9 FG, 6-9 FT) on 13 driving layups, because they had three shots blocked and missed three free throws. Their 11-of-17 shooting from the free-throw line in 23 pressure-filled minutes is troubling, and another shot block of their only attempt to find a cutter to the rim seems to have dissuaded them from further attacking the basket, but neither should deter them from continuing to play with force.

Nor should their drive-and-kick misses. The Celtics left five assists for Tatum and Brown on the table when they missed every catch-and-shoot 3-point attempt in these 23 dreadful minutes, but they have to trust the 1.12 points per possession that Horford, Smart and White have scored on those attempts in these playoffs.

Boston's willingness to burn clock and settle for isolation jumpers when big games get tight is almost as inexcusable as turning the ball over once every five possessions. Golden State is scoring 0.97 points per possession off of made field goals in this series. That number climbs above 1.00 off of missed field goals and up to 1.44 points per possession off of live turnovers. The Celtics are making it harder on themselves on both sides of the ball by essentially conceding half of their offensive possessions in these moments.

Good news, bad news

The good news for the Celtics is that they have solved this problem before. They have been the best passing team in the playoffs, throwing more per game (286.6) than any team that survived the first round and assisting on a postseason-best 66.2% of their field goals. Driving and kicking is their bread and butter.

In their Game 5 loss to the Bucks, the Celtics created just 12 catch-and-shooting chances and scored 10 points on those actions. They held the ball and dribbled at a rate that would have led the league in length of possession in the regular season. In their Games 6 and 7 victories against Milwaukee, Boston slashed its pull-up jump shots by more than 10 per game and generated 85 points on 72 catch-and-shoot chances.

They dribbled less, drove more, passed more and scored more. Pretty simple stuff.

The bad news is the Celtics knew all of this after a late offensive meltdown in Game 4 of the NBA Finals and played worse in Game 5, abandoning the offensive principles that got them here. They dribbled more, drove less, passed less and scored less. It is a trust issue, and when they lose faith in their ability to create for each other in this series, the Celtics only allow the snowball that is Golden State's offense to roll downhill.

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Ben Rohrbach is a staff writer for Yahoo Sports. Have a tip? Email him at rohrbach_ben@yahoo.com or follow him on Twitter! Follow @brohrbach