Whether you are an NHL general manager or just trying to manage your fantasy hockey roster, one of the best skills you can have is the ability to determine whether a player's success is small-sample luck or a trend that will carry throughout an entire season.
Through the first month of the season, we have seen some spectacular starts to 2018-19 by superstar scorers like Connor McDavid, Evgeni Malkin and Patrick Kane. Because of their histories, it doesn't take much effort to figure out that these Hart Trophy-caliber players will keep on trucking through the winter and spring. But there are a number of players whose blazing hot starts are much more questionable based on their past performances.
Let's have a look at five small-sample stars with bright seasons ahead, and five others who are likely to slow down soon:
The change is real
Morgan Rielly, D, Toronto Maple Leafs
Key stat: 16 goals for the Leafs with Rielly on the ice in 12 games
Why he can keep rolling: Toronto's hot offensive start has given a boost to a number of players' stat pages, and nobody more than Rielly, who is tied for the league lead in points by a defenseman (15). With a career high in on-ice shooting percentage, the potential exists for a slowdown, but there are a few other factors at play: Head coach Mike Babcock is giving him more offensively advantageous minutes, with an offensive zone start percentage 10 points higher this season than last, and he's posted a career high 52.6 Corsi for percentage and an individual shot rate that has jumped from 2.4 to 3.3 per game.
Rielly's shooting percentage is higher than ever, so Bobby Orr-style numbers aren't probably in the cards in the long term after that drops a bit, but he could certainly finish among the elite blue-line point producers, which would be a huge change from just 27 points two years ago.
Dougie Hamilton, D, Carolina Hurricanes
Key stat: 64.5 Corsi for percentage
Why he can keep rolling: Now settled in Carolina, the former Bruin and Flame is controlling the shot counter when on ice, at a preposterous rate. The Hurricanes are out-attempting opponents 2-to-1 with Hamilton on the ice, which is significantly higher than last season's league-leading Corsi for percentage by a defenseman, 60.4 percent. So why would it be plausible that Hamilton can continue helping the Canes dominate the puck at this level? Well, because last season, he was that league-leading defenseman.
The combination of an up-tempo system and his natural puck skills mean that Hamilton is able to quickly move the puck up ice to Carolina's shooters. It doesn't hurt that he's playing the vast majority of minutes with underrated blueliner Jaccob Slavin and up-and-coming star Sebastian Aho.
It's incredibly hard to keep a Corsi for percentage over 60 percent, but it's certainly plausible that Hamilton could be the player who tips the ice most in his team's favor league-wide.
Mitch Marner, RW, Toronto Maple Leafs
Key stat: 11 even-strength points in 12 games
Why he can keep rolling: There can't be many things more enjoyable in hockey than arriving at the rink knowing you are lining up alongside John Tavares. Marner has played 145 even-strength minutes next to the all-world center, and Toronto has produced 11 goals in that span. Marner has nine of his 11 even-strength points playing with Tavares, and with more than eight shots per 60 minutes and just a 6.2 percent shooting percentage, it wouldn't seem the high production has much to do with puck luck.
They also play together on the power play, where Marner has five of his 16 points. The fourth overall pick in 2015 is playing nearly three minutes more per game than last season. All signs point to a huge season continuing for Marner.
Gabriel Landeskog and Mikko Rantanen, W, Colorado Avalanche
Key stat: Landeskog is second in goals, Rantanen No. 1 in assists
Why they can keep rolling: There is reason to question both players' crazy-hot starts. Landeskog has never produced more than 26 goals in a single season, and that came in 2013-14. With 21 points, Rantanen is putting together a pace that would blow away his 84-point sophomore season. But there isn't much evidence that they will be slowing down so long as superstar Nathan MacKinnon remains with his favorite two linemates.
The trio has played nearly every even-strength minute together this season, and the Avs have outscored opponents 14-4 when the line has been on the ice. Landeskog's shooting percentage will dip from 29.4 percent, but he shot a solid 13.7 percent last season, meaning he can keep finishing the chances he's given. And here's a crazy stat: Rantanen leads the league in points, and he doesn't have an even-strength goal yet. He's owning a higher percentage of on-ice scoring chances (per Natural Stat Trick) than last season, at 52 percent, leaving the door open for the Landeskog-MacKinnon-Rantanen trio to be the runaway best line in hockey.
Antti Raanta, G, Arizona Coyotes
Key stat: 1.99 goals-against average
Why he can keep rolling: The Coyotes appear to have found their franchise goalie. Raanta, a former Henrik Lundqvist backup, had a tremendous 2017-18 season fly under the radar because of the team's struggles and his own injuries. He produced a terrific .936 even-strength save percentage (which is generally more predictive of future performance than all-strength save percentage) last season, carrying over the same mark from his 2016-17 fill-in days in New York. In eight starts this season, he's right on track with a .929 even-strength mark and a sub-2.00 goals against average.
Another stat worth noting is the consistency Raanta has displayed. Between New York and Arizona, the 29-year-old netminder has started 98 games and given his club 67 quality starts (defined as a start with higher than league average save percentage or fewer than two goals allowed).
Expect a slowdown
Kyle Palmieri, RW, New Jersey Devils
Key stat: Five power-play goals in nine games
Why he will slow down: Like some of his colleagues in the group above, Palmieri has struck gold playing minutes alongside an elite player. However, this isn't the first time the veteran winger has been given a chance next to Taylor Hall. Last season, they performed well together in 412 even-strength minutes, with Palmieri scoring 11 goals and 15 points in that span. This time, he already has notched four goals in 112 minutes with an absurd 33.3 shooting percentage.
The former Duck also leads the NHL in power-play goals. His career high is 11 power-play goals in a single season. At this pace, he'd score more than 40 power-play goals. While he's still in for a good season, that seems rather unlikely.
Viktor Arvidsson, RW, Nashville Predators
Key stat: Seven even-strength goals in 12 games
Why he will slow down: With five goals in his last five games, Nashville's undersized winger has jumped out to an incredible start offensively, which further works to solidify him as a quality top-line player after back-to-back 61-point seasons. Arvidsson is certainly the beneficiary of a great situation on a Stanley Cup contender, with Ryan Johansen and Filip Forsberg on his line, but sustaining his scoring rate does not seem possible without a huge jump in shot rate. He's currently scoring on 24.4 percent of even-strength shots, which is very likely to come back to earth considering it is more than double his shooting percentage in 2016-17 or 2017-18.
Elias Lindholm, C, Calgary Flames
Key stat: 13 points in 13 games
Why he will slow down: The door should be left open for the classic scenery change finally getting the most out of a top draft pick that didn't take off with the team that selected him; we have seen it many times before. In this case though, it would be quite surprising. Lindholm topped out at 45 points in a single season in Carolina as a top-line player. Now he's approaching star territory, with a point-per-game pace. However, Lindholm's 23.5 percent all-situation shooting percentage is 14 percentage points above his career mark, and his even-strength shooting percentage is three times what it was last season.
The good news for Lindholm is that he's playing minutes with scorers Johnny Gaudreau and Sean Monahan, and has an increased shot rate from the past. It's likely to be a good season for Lindholm, but not a superstar-caliber breakout.
Semyon Varlamov, G, Colorado Avalanche
Key stat: .950 save percentage, eight straight quality starts
Why he will slow down: While the Avs are going to keep getting offensive production from their skilled first line, it would be stunning if Varlamov put together a Vezina Trophy-caliber season like what we've seen so far. Since he finished second in the Vezina voting in 2013-14, he has a middle-of-the-road .917 save percentage. Last season, he was a shade above that at .920. He also hasn't topped a .923 even-strength save percentage since 2013-14.
Elias Pettersson, C, Vancouver Canucks
Key stat: 4.51 points per 60 minutes (all strengths), eighth in the NHL
Why he will slow down: The 19-year-old Swedish sensation has given Canucks fans reason to be optimistic about the team's long-term outlook with an offensive explosion in his first 10 games, producing seven goals and three assists.
Pettersson's outrageously high 36.8 percent shooting percentage makes him a cool-down candidate, but that certainly doesn't make the highly touted prospect a fraud. The fact that the Canucks have been dominant while the 2017 fifth-overall pick is on the ice suggests he can continue to have a major impact offensively. Vancouver has out-shot opponents 83-59 with him on ice, and Natural Stat Trick credits the Canucks with 81 scoring chances to opponents' 68 in his 133 minutes on ice.
So we might not see Pettersson stay at his current pace and score 50-plus goals, but the potential exists for a great rookie campaign and a good shot at the Calder Trophy.