Do the Celtics have a shot to emerge as contenders in the East? 5 reasons for optimism and 5 reasons for pessimism

At the moment, the Celtics feel like a significant other who knows they might be dumped and is buying flowers and chocolates last-minute to avoid a messy breakup.

Sometimes, though, those flowers and chocolates actually facilitate growth and help the couple realize it was meant to last all along. During this recent stretch, it’s difficult to figure out if the Celtics’ success is a sign of things to come or simply a major tease.

It’s up to each individual to determine whether or not they think they could emerge as legitimate contenders, but here’s a closer look to help fans make an informed decision.

Thumbs-up: They pass the eye test the majority of the time

When they play the way they’re capable of playing, the Celtics are actually quite fun to watch. They zip the ball around the court, the pieces mesh well together and everyone seems to be genuinely enjoying themselves.

As of Tuesday afternoon, the Celtics have the best net rating in the last month, ahead of even the Suns. They also have the second-best defensive rating and ninth-best offensive rating, and those numbers really do tell most of the story.

They’ve won four of five, and all four wins have come by double-digits. They’ve also won nine of 13, and five of those nine wins have come by 19 or more. Your eyes aren’t deceiving you. This is a good basketball team...for the most part.

Thumbs-down: But wait a minute, they’re playing mediocre teams and still can’t win close games

This is largely true, as the Celtics have taken care of the Magic, Knicks, Pacers twice, Pelicans twice, Wizards, and Kings of late. There’s nothing wrong with beating teams they should beat, and they also knocked off the Suns, shorthanded Bulls and shorthanded Heat, but they haven’t had a signature win since the Suns game.

They also dropped tight games to the Hornets and Blazers and lost a winnable game to the Hawks after an impressive comeback. With the Nets, Nuggets and 76ers on the horizon, a close win over one of those teams would go a long way in proving in how far they’ve come.

They’ve finally started to take two steps forward and just one step back, and now they need to keep it going when the competition stiffens.

Thumbs-up: Jayson Tatum and Jaylen Brown are complementing each other quite well

The crowd that believes the Celtics should split Tatum and Brown up hasn’t made a peep lately.

Both scored 30-plus against both the Wizards and Pelicans and have been in a rhythm individually and collectively. Brown averaged 26.1 points, 7.6 rebounds and 3.5 assists in January, and Tatum put up 27.0, 8.2 and 4.6 a night.

Now that Tatum’s brutal shooting slump is behind him, both players have looked outstanding of late – and not just by themselves.

Thumbs-down: When they struggle, the Celtics often do as well

It’s natural that a team’s production would dip when its star players struggle, but it’s pretty extreme with Tatum and Brown.

In Celtics wins, Brown is shooting 49.6 percent from the floor, 43.1 percent from 3-point range and 80.6 percent from the line. In losses, those numbers plummet to 42.2 percent from the floor, 28.9 percent from 3-point range and 77.7 percent from the line.

For Tatum, his splits are 45.4, 37.6 and 85.5 in wins, compared to 40.6, 27.2 and 83.0 in losses. The Celtics don’t really have a third scorer who can pick up the slack if they have an off night – think Chris Paul, Jrue Holiday or Bojan Bogdanovic. (Apologies to the crowd that believes Dennis Schroder is a good fit.)

Thumbs-up: The starting-five has looked terrific when healthy

The starting-five of Marcus Smart, Brown, Tatum, Al Horford and Rob Williams is 11-6 with a 117.5 offensive rating and 89.7 defense rating. Its plus-27.8 net rating is the second-best among the 19 five-man groups with 200 minutes.

Injuries and illnesses have prevented this unit from seeing the floor as much as Brad Stevens and Ime Udoka envisioned, but it’s looked pretty darn good when it’s gotten the chance. Smart, in particular, has played some of his best basketball of late and appears to be meshing as well with Tatum and Brown as ever.

Thumbs-down: The bench hasn’t consistently picked up the slack

So wait a minute...If the starting-five is elite, why are the Celtics struggling at times? The bench hasn’t always picked up the slack, even in wins.

Against the Pelicans, for instance, Williams and Smart were plus-28 and Tatum plus-17, while Schroder was minus-11, Grant Williams minus-10 and Aaron Nesmith minus-six. In the Heat game Monday night, every starter finished plus-24 or better, while every member of the bench was plus-five or worse in a 30-point win.

The bench players don’t need to play at a starting-caliber level. They simply need to exceed the production of the other team’s bench – which they’re not always doing at the moment. It’s difficult to gauge whether this trend will continue, but there’s no compelling evidence to think that it won’t.

Thumbs-up: They keep blowing teams out and are largely avoiding close games

One way to avoid having to win close games is to never have them at all.

Though they’re in ninth place in the East, their point-differential of 3.4 is third-best in the conference. Their defense has been elite of late, and they shot a season-best 46.3 percent from the floor in January.

They crushed the Wizards, 116-87, Kings, 128-75, and Heat, 122-92, and have scored 100 or more in eight of their last nine.

Thumbs-down: They often struggle in the fourth quarter

For whatever reason, the Celtics frequently look like a different team in tight games in the fourth quarter. Naturally, defense intensifies and most teams shoot lower percentages in the fourth, but for the Celtics, the trend is especially alarming.

They shoot 42.8 percent from the floor, 31.3 percent from 3 and 80.8 percent from the line in the fourth, compared to 44.9, 34.1 and 81.6 for the game. That fourth-quarter 3-point percentage, in particular, is the second-worst in the NBA behind only the Pistons. Part of the reason why? They average tied for the fewest-assists in the fourth quarter (4.9).

Their plus-minus of minus-0.8 is 22nd in the NBA and they turn it over the 10th-most (3.6). It’s no secret that Celtics would benefit immensely from finding some stability, moving the ball more and relying less on isolation looks late in the game.

Thumbs-up: Everyone in the Eastern Conference is all clumped together

As poorly as they’ve played in stretches this season, the Celtics are currently only 5.5 games back of the first-place Bulls. They’re only 3.5 games behind the Nets and four games behind the Bucks.

With games against the Hornets, Nets, Hawks and 76ers in the next two weeks, this is a pivotal juncture for the Celtics as they try to make up some ground.

Thumbs-down: Everyone in the Eastern Conference is all clumped together

This one is a double-edged sword. While the Celtics are close to the 6-seed, they’re also close to missing the playoffs entirely. The Knicks and Wizards have both been struggling, but they’re still only 2.5 games back of Boston.

It’s essentially three tiers at the moment, with the Bulls, Heat, 76ers, Cavs, Bucks and Nets all within two games of one another, the Hornets, Raptors, Celtics, Hawks, Knicks and Wizards all within 4.5 games of one another and the Pacers, Pistons and Magic already thinking about the NBA Draft. A lot can change quickly, for better or worse.

You make the call. Is this team a contender or a pretender? Only time will tell, and what the Celtics do at the trade deadline (if anything) could ultimately determine the trajectory of the season.