How has one of the NBA’s best defensive teams turned into a sieve? The Jazz are trying to figure it out, too.

Everyone knows the hallmark of the Utah Jazz is stingy defense, right? They can’t light it up like the Golden State Warriors, but they always, always make it tough for opposing teams to get baskets.

Except this year, they’re not. Through 10 games, they’re 13th in opponents’ points per game (110.2), 16th in the league in defensive rating (109.3), and an eye-popping 27th in opponents’ field-goal percentage (48.3).

After Monday’s 124-111 loss to Toronto — the team’s fourth straight defeat — some players expressed their dismay that they haven’t been able to fix the defensive woes yet.

“I wish I could say it would be easy," said Joe Ingles. "We have watched so much [film] over the last however many games, the whole year, really — even from the preseason. There’s things we need to do, things we need to get better at, the little things that made us so good last year, and we haven’t really done any of them to this point. We’ve played quarters, we’ve played minutes, but it seems like the runs that teams have against us — 20-0, 18-0, it’s not 8-0 and we can get a stop and regroup. It just kind of falls apart. We need to fix it quickly.”

Beyond the broad strokes, though, what specifically is it that needs to be fixed?

Well, for starters, per the analytics site Cleaning the Glass, the Jazz are having particular problems in allowing shots at the rim and in the midrange.

While Utah is doing a good job of limiting opponents’ opportunities at the rim — they rank seventh in the league, with just 33.7 percent of shots coming there — they haven’t been particularly good at stopping those shots. Teams are converting 65 percent of them, which ranks the Jazz 23rd.

It’s been even worse in the midrange. There, opponents are not only taking a high volume of shots (36.3 percent), they’re making 44.6 percent of them — which ranks the Jazz worst in the league.

“Teams [now] come here with the mindset of attacking us. You can feel it. We’re not the Utah Jazz of last year in their head, and they come in here trying to be aggressive,” said reigning Defensive Player of the Year Rudy Gobert. “… So it’s on us to get past that and be aggressive. We’ve got to set the tone; when we start setting the tone defensively, things are gonna go back to how they should be.”

At least on 3-pointers, the Jazz are faring a bit better. They rank eighth league-wide in limiting opponents to taking just 30 percent of their shots from deep. However, the narrative has been that Utah is allowing open looks, and the evidence bears that out, as the team drops to 19th in the league in seeing 36.7 percent of those 3-pointers go in.

That same story plays out as well on transition attempts. While the Jazz allow the fifth-fewest transition attempts in the league (14 percent), when opponents do get out on the break vs. Utah, they’re converting their chances. The Jazz ranks 20th and 22nd, respectively, in points per 100 possessions allowed via transition play, and points scored per 100 transition plays.

Coach Quin Snyder said that particular problem was especially apparent against Toronto.

“There was just space on the floor and we were getting driven. They’re a very good team attacking in the open court. … So we needed to get back with more urgency. And we needed to keep the ball out of the paint,” Snyder said. “We were getting driven, whether it be in pick-and-roll, where we weren’t keeping the ball where we needed it, close-outs; just a lot of situations where the ball was getting in the paint. When that happens, it’s difficult to recover on a possession.”

Furthermore, the players acknowledge that they haven’t been as assignment-sound as they ought to be. Against the Raptors, they made the mistake of going under screens against good shooters like Kyle Lowry and Fred VanVleet, allowing open 3s, and going over them against the poor-shooting-but-slashing Delon Wright.

“We haven’t been a unit," Ricky Rubio said after Tuesday’s practice. "One night it’s one guy making a mistake, and another play it’s another guy making a mistake. On defense, it has to be the five guys doing the right thing at the same time. One mistake, no matter what the other four have done, and the defense doesn’t count. We gotta take that personally. … We gotta be smart, we gotta know personnel, we gotta know who we’re playing against.”

To a man, the Jazz acknowledge that even when they’re getting the details right, they’re not doing so consistently.

That, as much as anything, needs to change.

“We’ve shown patches where we can be really good and be the team we know we can be, but we’ve shown a lot more of the other side of it to this point,” Ingles acknowledged.

Snyder agrees with that much. It’s not that his players haven’t been trying — it’s that they haven’t been doing the right things often enough.

“I don’t think there’s a lack of effort defensively, there’s a lack of focus. However you want to define that, our general effort needs to be better,” Snyder said. “… I think our team cares, we’re just not caring about the right things.”