“Unsustainable.”

It became last season’s rallying cry for those Calgarians who — despite what the numbers told them — believed in their Flames.

The mantra dripped with sarcasm, and among those who were in on the joke, it required no explanation. Every time the Flames engineered another comeback, or scored with their goalie pulled, Twitter reverberated with one-word posts: “Unsustainable!”

It was, of course, the word used by those who crunched the numbers on a team that was picked to be a doormat, and deduced that the team’s “luck” could not continue. Even Flames general manager Brad Treliving shared an analogy that has been running through the Flames’ front office over the summer:

“Our season last year was like winning the Masters,” he quipped, “while sinking eighteen 40-foot putts.”

The Flames were clearly able to overcome poor possession numbers, average goaltending, and ride a high shooting percentage to two rounds of playoff hockey last spring. But don’t think Treliving is kidding himself. He knows they could be the 2013-14 Toronto Maple Leafs, or the 2014-15 Colorado Avalanche, if they don’t pay heed to the numbers.

“We can’t just say the recipe for this season is ‘we’re going to win a bunch of games by coming from behind in the third period. We’re going to pull the goaltender eight times and score a tying goal in seven of them,’” Treliving said in an extended conversation with Sportsnet. “There are a number of things there you can’t rely on duplicating. We’re not saying we have to retrace out footprints from last season. We have to get better.”

Statistically, these are a few of the stats that coined the term “unsustainable:”

• Calgary had a third period/overtime goals differential of plus-36. The Flames required 10 third-period comebacks (third in NHL) in order to clinch a playoff spot in Game 81 of the season.

• The Flames had a shooting percentage of 10.5 percent, ranking second in the NHL. That allowed Calgary to score the sixth most goals despite being 28th in shots on goal. The average shooting percentage in the NHL last season was 8.9 percent, according to sportingcharts.com.

• Calgary’s top eight scorers last season all had career seasons in points, a group that includes rookie Johnny Gaudreau. Can the entire upper half of the roster have career years again?

• A 24th-ranked Corsi of 47.4 means the Flames just didn’t possess the puck at a level commensurate with a playoff team — let alone one that went two rounds.

“Any type of predictability (analysis) will tell you that you can’t continue to trail and expect to have successful outcomes,” Treliving admitted. “We’ve looked at it seven ways to Sunday. We can’t continue to dig holes, and consider a victory when we work … fill the hole back in. That just doesn’t win.”

In just his second year as GM in Calgary, Treliving can take solace in the fact he has built one of the top blue lines in the entire NHL, augmenting an already good back end with the savvy trade for Dougie Hamilton. It was a genuine surprise for the former assistant GM in Arizona, once he got a true eyeful of some of these Flames defencemen.

“I knew TJ Brodie was a good player. I didn’t know he was this good. I knew Mark Giordano was a good player. I didn’t know he was this good,” he said. “It was, in a lot of ways a revelation. Gio was better and did more than I could have envisioned.”

Deryk Engelland was better than anybody thought he’d be. Kris Russell, too.

“You add Dougie Hamilton to the mix, it becomes a pretty good blue line,” said Treliving.

He’s got an extra goalie, having signed Karri Ramo to a one-year deal at $3.8 million. Jonas Hiller has one year remaining at $4.5 million, and heir apparent Joni Ortio becomes waiver eligible this season. So, unless the Flames wish to carry three goalies this season, either Ramo or Hiller will be moved or subject to waivers — and it was Hiller who lost his job to Ramo in Round 2 last spring, after having been made available at the trade deadline in March.

So, the defence is better with a healthy Giordano and the addition of Hamilton. Ortio makes the goaltending better, and waiting in the wings is big Jon Gillies, who is turning pro as a No.1 in the AHL.

And with the addition of Michael Frolik and a full season out of Sam Bennett, how can the forwards’ ranks not be improved as well?

“Sam was very impressive in the playoffs, [but it’s] a very small sample size. He’s played in one regular season game last season,” cautioned Treliving. “This is new to him; he’s young, and we are not throwing him head-first into the deep end. We want to let this guy breathe a little bit, and find his game at his pace.”

There might not be time for that in Calgary this season. The Flames are a Round 2 team that requires the kind of start that will stop the “unsustainable” talk from creeping in.