Mathias Lange, Rensselaer Polytechnic Institute’s goalie who played just his third college hockey game Friday night (and first against an NCAA Tournament team), didn’t even need to pause to think about the question. Had he ever played against forwards with as much speed and skill as Boston University’s?

“Only once,” said the stoic, stone-faced freshman. “I played in the World Juniors for my native country, Austria. I played there when Team USA won it.”

But no one else he’s seen was as good as BU. And yet there he was, after 29 saves and just two goals allowed, explaining to the media how he was so good. Not to take anything away from Lange, who played fine, but he’s probably never going to win a Vezina. Maybe it wasn’t so much him.

BU coach Jack Parker was quick to blame his team’s ugly, unacceptable 3-2 loss to the Engineers on a slew of defensive breakdowns that gave RPI, as Parker said, more odd-man rushes than one of his teams has given up in years. And he certainly has a point.

But the real reason for the sour smell inside Agganis Arena around 9:30 on Friday night? That would be the same culprit as a lot of BU’s big, bad losses over the past few years: a complete and shocking inability to convert on dozens of golden scoring opportunities.

The Terriers came out in this game with so much jump and adrenaline that on three first-period RPI power plays, the Engineers barely entered the BU zone. RPI didn’t have a shot on John Curry until almost 15 minutes into the game. All of these things signaled a fired up, energetic, good hockey team.

But BU also didn’t have a goal through 15 minutes. A couple great Jason Lawrence chances ended up either in Lange’s pad or wide of the goal. Kenny Roche hit the post. Pete MacArthur couldn’t convert after a pretty toe drag. Almost every time the puck sat in front of Lange (which was often), it never got batted home.

“We were right on the doorstep a couple times and shot it wide or the kid made a great save. I thought we had some good chances the rest of the game, too, but that wasn’t the problem,” Parker said.

But it is a problem, and a big one. Sure, it’s unacceptable that the Terriers stopped playing defense midway through the second. But if they already had a big lead – which they should have – then it wouldn’t have happened, and even if it had, there would have been enough of a cushion to allow for a successful adjustment.

After RPI finished weathering BU’s 15-minute opening flurry, John Laliberte did convert with moments left in the first. And it was a gutsy finish, too – with a defender draped over him, Laliberte wriggled free to slam home Brad Zancanaro’s pass.

And minutes into the second, Brandon Yip and Roche combined for another tally, when each player fought through a hit on the way to Yip’s first collegiate goal.

At that point, with a two-goal lead (the most dangerous lead in hockey), it felt like the Terriers were up about 10. And that’s what caused their breakdown.

“Once we got up, we thought it was gonna be point night,” Parker said.

There would be no more points, though. When they needed goals down the stretch, they didn’t get them. They looked more frantic than urgent in the final minutes, whiffing on good opportunities and failing to connect on passes. Lange never had to stand on his head in the third, despite 10 BU shots on goal that gave the Terriers a 31-13 edge for the game.

“You don’t add up the yardage,” Parker said. “You only add up the score.”

Scoring has been the sore spot for the Terriers for years now – the problem is nothing new. The RPI game looked a lot like the many BU lost two years ago, when it drastically outshot an opponent only to fail to take advantage. Lange isn’t the first young goalie who’s made his first trip to the press room after playing the Terriers.

Playing bad defense, having their minds on the wrong thing – these are things that can be addressed. Having a dead-on finisher or two, though – that’s a little harder to remedy.

So far, the Terriers still don’t have one, and they’re probably not going to get too far if one – maybe Lawrence; maybe a rejuvenated Dave Van der Gulik; maybe MacArthur? – doesn’t emerge. It’s why they lost to the University of North Dakota in the NCAA Tournament last year. They had the same problem against UMass-Lowell last week in the season-opener, but good defense made their three goals stand up. But if they’re losing to RPI at home this year because of it, it’s not a good sign.

“It’s early in the season,” Laliberte said. “We’ll get the lines shuffled around and get some guys playing with each other. Whoever feels comfortable, it’ll be apparent out there on the ice. Tonight maybe we didn’t have a couple lines clicking. It’s early in the season. There’s still a lot of time left.”

The clock moves quickly when you can’t score, though. Zancanaro, admirably fulfilling his captain duties after Parker anointed him the only Terrier who played well Friday, didn’t make any excuses.

“We had the chances to score goals, and we didn’t score goals,” he said. “Their goalie played pretty well, we had a lot of shots, a lot of opportunities like backdoor or whatever.

“But you gotta bury those chances.”

But can they?