Throughout Bill Tierney’s tenure as Denver men’s lacrosse coach, the Pioneers have been defined clearly by their offensive identity.

For years under coordinator Matt Brown, the Pioneers have dictated games by controlling possession time, forcing the pace, creating transition and attacking with an aggressive six-on-six approach.

Denver’s inverts and pick-and-rolls and isolation strategies have flowed through a handful of scoring threats, spiced with Canadian flair. The Pioneers have worn out defenses with a stable of excellent shooters who have pounded opposing goalies into submission with one of the highest scoring units in the game.

When a freshman phenom named Trevor Baptiste took over at the faceoff X in 2015, Denver had the perfect straw to stir its drink. After knocking on the door to a national title for several years, the Pioneers broke through that year to win the first-ever NCAA tournament in school history.

One thing hasn’t changed much out west. With Baptiste commanding his role by playing keep-away like no other FOGO in NCAA Division I history, Denver has remained a serious championship contender.

For the 2018 Pioneers, however, much has changed. This year, Denver has deviated from their script in ways that Tierney did not foresee. The Pioneers have morphed in part into a throwback in Tierney’s former image, as the coach who led Princeton to six national crowns with the sport’s most suffocating defense.

Believe it. The fifth-ranked Pioneers (11-2) are heading into the Big East tournament semifinals against Marquette on Thursday with the stingiest defense in Division I. Through its first 13 games, Denver ranks first in the country, having allowed just 7.46 goals per contest.

Not that Denver is unable to score goals at a prolific rate, far from it. Not with the NCAA-record setting Baptiste leading a faceoff unit that has won a ridiculous 78 percent of its draws this season. Just ask Big East rival and tournament host Villanova how potent the Denver offense can be. The Wildcats endured a 22-6 beat-down by the Pioneers at home on April 6.

But that result, another in an interrupted string of Big East wins — Denver has never lost a regular-season match since joining conference — represents an outlier in an unusual season for the Pioneers.

Their 2018 campaign has been marked by puzzling, inconsistent offense by Denver standards. Whether it’s been turnovers or up-and-down shooting or a lack of consistent scorers to support the remarkable attack duo of Ethan Walker and Austin French, the Pioneers have leaned hard on possession time advantages and on an underrated, tenacious defense that has become fairly stout.

“There is a chemistry that has really developed, through John’s coaching. He has molded this unit,” said Tierney, referring to defensive coordinator John Orsen. “They make mistakes, but not the kind of mistakes that cause us to give up too many goals. Our guys have figured out how to communicate. They know where each other is going back there. I don’t think a lot of people realize how good this defense is.”

Led by junior close defensemen Dylan Gaines and Dylan Johnson and sophomore short-stick midfielder Danny Logan, this is how good the bottom line says Denver has become at the back end.

This is how well the Pioneers have thrived on defense, despite not having a consistent starter in goal until recently with sophomore Josh Matte, and despite losing their most talented defender in senior long-stick midfielder Sean Mayle. He had missed the last five games, before officially being ruled academically ineligible for the remainder of the year.

In 10 games — all victories — the Pioneers have held opponents to single digits. Eight times, Denver opponents have failed to reach eight goals. During its current seven-game winning streak, Denver has stifled opposing offenses by allowing 6.3 goals per game. The last time it gave up more than six goals was on March 24, when the Pioneers rallied to beat visiting Towson in overtime 11-10.

That day, the Pioneers scored just one goal in the first half, a stunning level of futility they would repeat a week later at Georgetown, before coming back to take a 6-5 decision. Starting with that day in Washington, D.C., Denver finished the regular season with five straight wins, allowing 5.4 goals per victory.

Make no mistake, the defensive numbers are tied in part to the amazing consistency of Baptiste, who shortens games almost single-handedly from week to week.

Opponents have limited transition by scrambling back to mute Denver’s fast break. When they gain possession, Denver opponents have slowed games to a crawl, handling the ball like a newborn on many possessions and welcoming stalling calls.

It’s simply sound strategy if you’re facing the Pioneers.

Denver is averaging 12.15 goals on 35.2-percent shooting, which rank 12th and sixth in the NCAA, respectively. Any team would take that without complaint. But the Pioneers, whose only losses are to Duke (15-12) and Notre Dame (11-9), are averaging 34.5 shots — a pretty conservative amount by their standards.

And outside of Walker (42g, 21a) and French (21g, 26a), who have combined to score 43 percent of Denver’s 254 points and shoot an outstanding 52 percent, the rest of the team’s shooters have struggled to get above 30 percent.

Ultimately, it comes back to Orsen’s group. Gaines (15 caused turnovers, 32 ground balls) and Johnson (13 CT, 17 GB) have been underrated lockdown defenders for some time.

Logan, a former first-line midfielder, has been a terrific stopper along with Zach Runberg, as they’ve combined to scoop 48 ground balls. Senior Matt Jones and junior Jon Ober effectively have patched up the hole in Mayle’s absence.

And Matte has emerged, for now, as the No. 1 choice in the cage, where Matte and junior Alex Ready have split time and have struggled to bridge the 50-percent save percentage line. Yet their bottom line defines the strange-looking success of this defense on paper.

How, one might ask, can a team lead the NCAA in fewest goals allowed and rank dead last with seven saves per game? How can a defense this solid force only five turnovers per contest? Again, credit Baptiste for creating lower playing time and thus, lower risk for the Denver D.

Perhaps the most contradictory defensive stat in Denver is this: When opponents have gone man-up, Denver has made stops just 61.5 percent of the time — making the Pioneers 52nd in man-down efficiency. That’s obviously nothing to brag about.

But the Pioneers have minimized that defensive glitch with admirable discipline. They have basically refused to foul, allowing just 26 extra-man chances. Only Army and UMBC fouled fewer times to this point in 2018.

Denver has allowed just 10 EMO scores this year.

It’s anybody’s guess how Denver will navigate the postseason of this unique year. The Pioneers might need to win the Big East again to secure a first-round home game, mainly because victories over North Carolina, Towson and Ohio State have lacked RPI juice.

The Pioneers could erupt offensively in May, or not. They could win several games by scoring in single digits, or not. But one thing seems certain. Wherever the Pioneers end up, they will likely get there in unusual ways. It’s been that kind of season in the Rockies.