The game has changed. And with it, so have the intricacies of the personnel you need to succeed in the NHL.

It's not necessarily near the top of the checklist for most teams, but having a second option in net that's somewhere between perfectly serviceable and legitimately reliable is something that has progressively evolved from luxury to borderline necessity. A good backup goalie in today's game is one of those things that you don't really appreciate the importance of until you don't have it, at which point it might be too late.

So which teams have done the best jobs of finding two reliable goalies? Which teams have an imbalance in one direction or the other? Who isn't getting good netminding from anyone this season?

Are workhorse goalies an endangered species?

With the modern advancements in and embrace of sports science in hockey circles, teams seem to have wised up to the dramatic effects that fatigue can have on goalie performance. Long gone are the days where we'd see Martin Brodeur and Miikka Kiprusoff routinely starting all but a handful of their team's games.

Last season no one started more than 67 games, and this season Marc-Andre Fleury is the only one whose pace is even close to approaching 70. Most No. 1 goalies are now firmly entrenched in the ballpark of 60 to 65 appearances in a given season, just as importantly almost never being asked to shoulder the load for both legs of a back-to-back scenario anymore.

We've come so far on this particular subject that when the Edmonton Oilers trotted Cam Talbot out for a whopping 73 appearances in 2016-17 (and another 13 playoff starts on top of that), it was publicly ridiculed as borderline malpractice on their part. It's impossible to say how much that workload was responsible for it, but he has been a shell of himself ever since.

Just because there's now a new accepted norm for how goalie starts should be split up doesn't mean that it has been a seamless transition for all. Teams are still trying to figure out how to walk the tightrope of optimizing their chances of winning on the occasions their starter does get a night off, without derailing their goalie prospects' development by having them sit on the bench all night.

With so few chances for the prospects to play, proportionally speaking, NHL teams have typically erred on the side of caution when it comes to calling those prospects up, instead preferring to get them more reps in the AHL. While that makes sense, it has resulted in a recycling of suboptimal veteran backups around the league, meaning that there are many instances where teams are using a goalie because he is a known commodity even if he isn't necessarily the best puck-stopping option available to them. Considering how tight the standings are, the margin for error is exceedingly small, and throwing valuable points away on those occasions is a tough pill to swallow.

Some teams have expertly found a way to have their cake and eat it too, while others have mightily struggled to string together enough of those secondary quality starts. And then there are the teams that have a bit of a power struggle going on, where they might need to reconsider who their best option really is. Here's a breakdown of that for each team, with the starter's save percentage on the x-axis and the backups on the y-axis. Note that the "starter" tag for each team has been designated to the goalie who has started the highest number of games for them this season:

The good

The top right quadrant is where you want to be on this chart. Six teams -- the Bruins, Penguins, Stars, Islanders, Sabres and Ducks -- have separated from the pack when it comes to always having the benefit of top-flight netminding regardless of who's playing.

We've already talked enough about John Gibson's unparalleled heroics in this space this season. Ryan Miller was actually very good himself in limited appearances for the Ducks before he went down with an injury, which is why they appear here, but the Ducks still rely significantly more on their starter than any of those others do. Anaheim will go as far as Gibson can carry the team this season, and not a single step further.

The Stars and Islanders are both either currently sitting in a playoff spot or right on the bubble largely due to where they land on this chart. Despite the fact that both teams are hovering around the 50 percent threshold for expected goals and have relatively pedestrian underlying shot share profiles overall, they're getting quality goaltending every night, regardless of who's in net.

The Isles' combination of Thomas Greiss and Robin Lehner has been good for fourth in goals against per 60 minutes and second best in save percentage. The Dallas duo of Ben Bishop and Anton Khudobin has given up the fifth-fewest goals and is currently sporting a league-best adjusted save percentage. All four are north of .920 for the season in save percentage, which is rather remarkable during a season in which the league average is below .910 for the first time in a decade. Any way you slice it, they've all been nothing short of fantastic, and aside from maybe Bishop, it's fair to say that none of them entered the season with any sort of real expectations or hype.

Being able to alternate goalies without any discernible drop-off has provided a massive competitive advantage to the two teams thus far, and will surely be even more valuable in the later stages of the season when injuries and fatigue begin to take an even bigger toll across the league.

That may be of particular importance to the Sabres, who are asking Carter Hutton to wade into personally uncharted waters this season. He has been excellent in his first season in Buffalo, but he's already nearing a career high in starts at this level with three months still to go. He's at 28 right now, which is the second most he has ever played, behind the 34 starts he made for the Predators in 2013-14. You could make the argument that means he has less tread on the tires than your typical 33-year-old goalie, but it's still tough to ask a goalie to play this much more than he ever has before while maintaining his current effectiveness.

The Penguins are interesting because they haven't taken the smoothest path toward getting to this point. They came into the season expecting Matt Murray to be their workhorse starter, but after he stumbled out of the gate with an .893 save percentage in October and .850 in November, they needed to turn to Casey DeSmith to carry them.

DeSmith been surprisingly stellar all year, stopping 92.4 percent of the shots he has faced and sitting 10th in goals saved above average at 7.12, just ahead of Pekka Rinne. Since returning from injury in December, Murray has looked much more like the goalie we'd come to expect during his dominant postseason runs, stopping a sparkling 96.3 percent of the shots he has faced in eight games during that time. If he keeps playing that way, he'll surely relegate DeSmith to the backup role they'd initially envisioned for him, which would be a great problem for Pittsburgh to have.

Similarly, the Bruins presumably want Tuukka Rask to be their starter, but thus far he has been outplayed by Jaroslav Halak. Halak's 12.27 goals saved above average is second to only Gibson this season, as both Halak and Greiss have shown that last year's dip in play was more indicative of the Islanders team in front of them than their own individual abilities. It'll be fascinating to see whether they Rask and Halak continue splitting starts evenly down the middle moving forward, and whether a goalie controversy eventually bubbles up if Rask once again struggles in the playoffs. That may ultimately be a moot point though, because it's quite possible that Halak's help shouldering the regular-season workload will result in a Rask who is fresher than he has been in the past come the postseason.

The bad

Mike McKenna is the seventh goaltender to start a game for the Flyers this season. Len Redkoles/NHLI via Getty Images

The bottom left quadrant is the one you don't want to find yourself in, so it should come as no surprise that that's where the Flyers show up. Brian Elliott was decent for them while he was healthy in the early going, but despite the fact that he has technically started the most games for them, they've had to split 30 of the other 43 games among six other goalies.

The carousel of Cal Pickard, Anthony Stolarz, Carter Hart, Michal Neuvirth, Alex Lyon and Mike McKenna combined to stop a stunningly low 87.4 percent of the shots they've faced in that time, and that 30th-ranked goaltending is ultimately the biggest reason why the Flyers have gone from playoff team last season to 30th in the standings and 31st in goal differential.

ESPN On Ice This week's episode makes some ESPN On Ice history. To incorporate the voice of the listener, Greg Wyshynski and Emily Kaplan opened up the phone lines to field great hockey questions from our loyal fan base. Plus, find out if we get stumped by this week's "Sach Got Your Number." And Linda Cohn advises what the New York Rangers should do in the way of future front-office moves. Listen »

The same ultimately goes for the Senators, but in their case it's tough to place the full blame on the goalies because they've been thrust into such a dreadful situation. The 37.1 shots per game that they're conceding isn't just the highest total in the league, it's the most porous defensive effort we've seen since the expansion 1974-75 Washington Capitals, and the fifth worst all time.

They're so bad defensively that they make last season's Islanders look like the neutral-zone-trapping New Jersey Devils, which is saying something, because that team seemed to have no clue what it was doing in its own zone. Still, the .882 save percentage from the Senators four goalies not named Craig Anderson certainly isn't helping cover for those mistakes. It's tough to imagine that things could possibly get worse in that regard, but if they do wind up trading Mark Stone, one of the best defensive forwards in the game, that's exactly what'll happen.

We're rapidly approaching trade season, and a name we'll presumably see attract a ton of interest will be Red Wings starter Jimmy Howard. This summer's free-agent goalie class is highlighted by Sergei Bobrovsky and Semyon Varlamov, but considering that the Blue Jackets and Avalanche view themselves as playoff teams at the moment, it's unlikely that we see either dangled as trade bait. With the Red Wings headed for the lottery, that makes Howard even more enticing to a contender as the next-best rental option that's readily available. On his part, Howard has done wonders for his trade value despite the very pronounced lack of support in from of him. It has been some time since he managed to be both healthy and good in the same season -- you'd have to go all the way back to the 2012-13 lockout-shortened campaign, when he had a .923 save percentage while starting 42 of the team's 48 games -- which makes this bounce back particularly well-timed.

His .916 save percentage isn't jaw-dropping by any means, but it's important to consider the context. In today's league it's well above average, but it's especially impressive given the team in front of him. Playing behind the same defense, Jonathan Bernier has been an absolute mess between the pipes for the Red Wings. The gap in performance between the two is among the largest of any starter and backup in the league, which might not actually be the worst thing in the world for Detroit.

For a team that's firmly in the asset-collection phase of their rebuild, anything the Red Wings are able to get for Howard at the deadline is found money in and of itself. But beyond that, once they trade him they'll presumably fall even further down the standings and improve their lottery odds in the process, because he has been one of the few things keeping them competitive in the first half of the season. Bernier being on the books for another two years after this one isn't particularly palatable, but it's likely going to be a couple of seasons before they're realistically able to compete again regardless of what they do. Using this as an opportunity to load up on high draft picks isn't the worst way to go about building things back up.

The TBD

David Rittich entered the 2018-19 as somewhat of an unknown commodity. But he has emerged as the Flames' best option in net. Bill Smith/NHLI via Getty Images

Goaltending can be volatile and unpredictable at times, but it's awfully tough to consistently win without good netminding. As such, it's not particularly surprising to see that a common thread among the top teams in the league is that they're mostly all set in net. Of the bunch in the upper echelon, there's only two that have legitimate questions yet to be answered; conveniently enough, they're both in the Pacific Division.

The NHL on ESPN+ Catch 300-plus NHL games streaming live or on replay this season on ESPN+. Click here for the upcoming schedule and to learn how to subscribe.

The Flames are putting together an intriguing case to be taken seriously as not only a viable contender to come out of their own division, but actually challenge the top teams in the Central for Western Conference supremacy. Only the Lightning have been scoring more goals this season, and it checks out because the Flames' offensive attack, led by Hart Trophy candidate Johnny Gaudreau, looks totally legit.

For them to ultimately take that next step in going from exciting team to real contender though, they really need to hope that David Rittich can keep up this level of play, and need to stop playing Mike Smith under any circumstances.

Rittich has been great this season, quickly wrestling the starting gig away from the incumbent without any shadow of a doubt. He's sporting a .921 save percentage in 25 games. His 6.42 goals saved above average is 13th best in the league, which is actually brought down by special-teams performance because his 10.42 goals saved at 5-on-5 are second to only John Gibson. The issue is that he had only 22 NHL games under his belt prior to this season, and before that all the data we had on him came from the underwhelming Czech league and limited AHL appearances.

In cases like this, it's fair to be cautious and have reservations until we see a player like him continue to do it over a larger sample. To Rittich's credit, he has been passing all of the required tests every step of the way with flying colors. Still, regardless of your level of confidence in him moving forward, it'd make plenty of sense for the Flames to explore bringing in a more reliable second goalie option to avoid entirely burning him out. For as little information as we have about how good Rittich really is, we have plenty to reliably say that Mike Smith is cooked at this point.

Of 72 qualified goalies this season the -11.73 goals saved above average rate for Jake Allen is the only one worse than Smith's -11.29. If you stretch it back to the final two months of last season, when Smith came back from an injury, he has stopped just 88.5 percent of the near 1,000 shots he faced in those 35 games. He has quickly become a liability every time the Flames play him, and the sooner they accept it the better for everyone involved. For those who remember his glory days, it has been sad watching Smith flop around while pucks sail past him in and into the net this season.

One final note: It's remarkable that the Sharks are as high up the standings as they are despite the goaltending that they've received from both Martin Jones and Aaron Dell. San Jose is 31st in save percentage as a team at 5-on-5 and 29th in all situations. For some context, the other teams living in that neighborhood are the Senators, Flyers, Panthers and Blues, which speaks to both how instrumental goaltending is for team success and how dominant the Sharks have been in every other facet of the game.

In The Crease Postgame analysis and highlight show airing each night throughout the season from Barry Melrose and Linda Cohn. Watch on ESPN+

The way the Sharks have managed to power through their goalie woes and avoid having it submarine their entire season has been admirable, instead using sheer volume of shots to swing the pendulum in their favor. Their 56.4 percent shot share is tops in the league, rivaled only by past seasons from Stanley Cup champions like the Red Wings, Blackhawks and Kings. Their 55.2 percent expected goals rate at 5-on-5 is third behind the Hurricanes and Lightning, and their power play is ranked seventh in goals generated per 60 minutes.

The biggest driver of that success has been Erik Karlsson, who has been playing at full throttle for a month now. There has been a lot made of his current scoring streak -- 25 points in 14 games will do wonders for capturing people's attention -- but the reality is that he has been his usual great self all season, even before the results caught up to the process.

With Karlsson on the ice this season at 5-on-5, the Sharks have controlled a staggering 60.1 percent of the shot attempts, 58.6 percent of the shots on goal, 54.4 percent of the actual goals and 60.7 percent of the expected goals. Now that he's all the way up to third in overall points for defensemen, it wouldn't be surprising to see his name getting mentioned once again in what's a wide-open Norris Trophy race this season.

But for the Sharks to finally take that big step and win the Cup with their current core intact, they're going to need more from Jones and/or Dell, or someone they acquire ahead of the trade deadline.