Yes, Rielly is off to one of the best starts by a defenseman in NHL history. He has 13 points (three goals, 10 assists) in six games for the Toronto Maple Leafs and ranks second in the League in scoring behind teammate Auston Matthews, who has 14 points (10 goals, four assists).

[RELATED: Matthews scores 10th goal, Maple Leafs win]

Only two other defensemen have had at least 13 points in his team's first six games of a season: Harry Cameron, who had 15 points (nine goals, six assists) for the Toronto Arenas in 1917-18, and Paul Reinhart, who had 14 points (five goals, nine assists) for the Vancouver Canucks in 1989-90.

But what does that mean?

In the little picture, nothing more than Rielly is incredibly hot entering the Maple Leafs' game against the Los Angeles Kings at Scotiabank Arena on Monday (7:30 p.m. ET; SNO, FS-W, NHL.TV).

As Rielly pointed out himself, there is luck in involved. When he had four assists in a 7-4 win against the Dallas Stars at American Airlines Center on Tuesday, one came on an empty-net goal.

"You kind of take it with a grain of salt," Rielly said before he had a goal and an assist in a 5-3 win against the Detroit Red Wings at Little Caesars Arena on Thursday. "You want to keep rolling. You want to play well. But I don't think it's sustainable. We'll see."

This pace is not sustainable, no, even if Maple Leafs forward Mitchell Marner called Rielly "Mo Orr" after the Detroit game. At that point, Rielly had 12 points (three goals, nine assists) in five games, breaking Orr's record of 11 points (two goals, nine assists) in five games with the Boston Bruins in 1973-74.

Video: TOR@DET: Rielly finishes off Marner's sweet feed

In the big picture, though, this could be an indication Rielly is coming into his own with the Maple Leafs as a team, as Keith did with the Chicago Blackhawks.

Keith entered the NHL in 2005-06. He had 21 points (nine goals, 12 assists), 31 points (two goals, 29 assists) and 32 points (12 goals, 20 assists) in his first three seasons, as Chicago finished 28th, 26th and 20th in the League.

But meanwhile, the Blackhawks selected center Jonathan Toews No. 3 in the 2006 NHL Draft and forward Patrick Kane No. 1 in the 2007 NHL Draft. They hired coach Joel Quenneville on Oct. 16, 2008 and signed forward Marian Hossa as a free agent on July 1, 2009.

Keith had 44 points (eight goals, 36 assists) in his fourth season, as Chicago made the Stanley Cup Playoffs for the first time in six seasons and broke out in his fifth with 69 points (14 goals, 55 points). He won the Norris Trophy as the NHL's best defenseman. The Blackhawks won the Stanley Cup.

Rielly entered the NHL in 2013-14. He had 27 points (two goals, 25 assists), 29 points (eight goals, 21 assists) and 36 points (nine goals, 27 assists) in his first three seasons, as Toronto finished 23rd, 27th and 30th in the League.

But meanwhile, the Maple Leafs selected Marner No. 4 in the 2015 NHL Draft and Matthews No. 1 in the 2016 NHL Draft. They hired coach Mike Babcock on May 20, 2015, and signed forward Patrick Marleau on July 2, 2017, and center John Tavares on July 1, 2018, in free agency.

Video: TOR@CHI: Rielly nets OT winner for the Maple Leafs

Rielly had 27 points (six goals, 21 assists) in his fourth season as Toronto made the playoffs for the first time in four years. He jumped to 52 points (six goals, 46 assists) in his fifth and could be breaking out even bigger now.

The comparison isn't perfect. For starters, Keith was a second-round pick (No. 54) in the 2002 NHL Draft and entered the NHL at 22, whereas Rielly was the No. 5 pick in the 2012 NHL Draft and entered the NHL at 19.

This is not a prediction that Rielly will win the Norris Trophy this season, let alone his first of two, like Keith did, or that the Maple Leafs will win the Stanley Cup this season, let alone the first of three championships in six years, like the Blackhawks did.

The point is that it can take time for defensemen to mature, and when you're a skilled player, having other skilled players around can bring out your best. Keith's maturation coincided with the injection of talent up front in Chicago and led to big things for him and his team. Something similar could be happening with Rielly in Toronto.

"It's a hard league for a [defenseman]," Babcock said. "We've got good offensive players up front, and Morgan can pass and really skate. … [Rielly] has got confidence. No one gives it to you. You've got to earn it. And I think he earned a lot last year and he's really come on again this year. He feels like every night he goes out there he can do something."

Rielly isn't spending as much time in the defensive zone. Now when he makes outlet passes, or joins the rush, or plays the point on the power play, it's with the likes of Marner, Matthews, Marleau and Tavares. When you play in the offensive end, you have more chances to be lucky. When you play with the lead, you have more chances for assists on empty-net goals. That's how you get rolling like this.

"There's been a lot of turnover in terms of personnel, lots of new players," Rielly said. "Management, coaching staff, has all changed since I've been here. It's been interesting to watch, seeing both ends of the spectrum, for sure.

"But I think when you look around the room now, I mean, we're a confident group. We like who we have here. We have confidence in our structure. We're all very comfortable with one another, and I think it's just a good environment to be in for a player. I think we enjoy being around one another and on a night-to-night basis we really enjoy coming to the rink. And I think that's really contagious.

"For a group to be going through this stuff with [Matthews] playing the way he is and [Tavares] and [Marner] playing together the way they are, I think it's just really exciting and fun to be a part of."