Apologies to the Utah Mammoth and Anaheim Ducks, but this is where the real test begins for the Vegas Golden Knights with their first serious opponent. The Colorado Avalanche were the league’s best team this season, are 8-1 through the first two rounds, and don’t appear to be slowing down anytime soon. That’s a big step up from a couple of 92-point teams.Colorado is the team to beat, a measuring stick for any team hoping to be the league’s very best. Do the Golden Knights stack up well as the Pacific’s best offering or will they be cannon-fodder to an actual contender?The oddsPerhaps that’s a little harsh. Yes, Vegas only managed 39 wins and 95 points this year and yes, getting by the Mammoth and Ducks isn’t that impressive. But all year, it felt like the Golden Knights were a much better team than their record indicated.That’s indicated well by their odds above: right in line with Minnesota’s chances against Colorado in the second round. In fact, they’d be even better if we had any sense of certainty about Mark Stone’s availability (we’ll get to that). What that means: If you thought the Wild were a serious team in the scary Central and a legit contender, a healthy Golden Knights team grades out just a little better.Here’s what it also means: Even if Vegas is a legit contender, the Avalanche are in another realm above that.Colorado looks like an unstoppable monster right now and starts the series as considerable favorites for good reason. It’ll take Vegas’ very best to climb that mountain.The numbersJust how strong do the Avalanche grade out by the numbers? A plus-84 Net Rating.While Colorado’s opponents have progressively gotten stronger along the way, from L.A. at a plus-nine, Minnesota at a plus-45 and now Vegas at a plus-55, no one has been able to measure up to Colorado.What separates the Avs and Golden Knights, above all else, is offense, with 26 goals between them.Colorado’s five-on-five offense dominated the regular season, ranking first in shot volume, xG and scoring. And that’s stayed a threat through two rounds; while the Avs’ scoring chance creation is a shade lower so far compared to the regular season, their shot generation and goal scoring are still overwhelming.The power play has been pretty dynamic, too. Now Colorado has to prove it isn’t solely thanks to a matchup against a short-handed Wild team. Vegas will be a test, considering how effective and disruptive its penalty kill has been lately.Vegas could have the complete special-teams edge in this series if the first two rounds are an indication of what’s to come. After a slow start, the Golden Knights got their power play back on track, and they have a good chance of breaking through against an Avs penalty kill that has been a little leaky.Five-on-five play tilts back toward Colorado, though, especially after Round 2. The Golden Knights were one of the top even-strength teams of the regular season and Round 1. While they outscored the Ducks 11-8, they didn’t control play as much, which likely won’t fly against this caliber of opponent.The big questionWhen will Mark Stone return?The way the Golden Knights closed out Anaheim — in a 5-1 win that was a bit of snooze, outside of some remarkable stuff from Mitch Marner — it might’ve been a little too easy to forget that, for a third straight game, Mark Stone was out of the lineup. Stone, after a relatively healthy season (and for him, 60 games counts), left Game 3 with a lower-body injury that was serious enough to stop him from being even a game-time decision.Give the Golden Knights credit for handling their business without him, but if his absence continues, it’ll drive their already-high degree of difficulty against Colorado into the stratosphere. Without Stone, their odds would dip from 37 percent to 30. Our odds project a Game 3 return, but that’s obviously murky.The Avs, of course, are dealing with injuries of their own; winger Artturi Lehkonen and defenseman Sam Malinski, both key contributors, are day-to-day. Neither, though, is their team’s second-best player — and that’s something you could credibly claim about Stone, regardless of the regular-season time he inevitably misses.The differentiation point with Stone compared to other high-end forwards, something Jack Eichel and Marner also add to the mix, is elite defensive impact. With a projected Defensive Rating of plus-3.3, he leads the way among Vegas forwards and, if healthy, contributes to a layer of two-way excellence at the top of the lineup that even other playoff teams can’t match.In the regular season, Stone scored 1.46 all-situations goals per 60, which was 23rd in the league among forwards with at least 1,000 minutes played, putting him just a tick behind Tage Thompson, Connor McDavid and Leon Draisaitl. He also remains one of the best playmaking wingers in the league, with a high shot-attempt rate and a primary assist rate (1.61 per 60) that tied him for seventh overall. Bundling that production with elite work in the defensive zone is rare, and a big reason to believe in Vegas’ upset chances.