I refuse to label a player as a #1 defenseman if they can't play defense.
He's an average/good #3 in my books. Needs to be sheltered with a defensive partner.
If the man could learn to defend a 2 on 1 my love would grow.
If he was a #3, that means there are about 65 guys in the league better than him on defense... I sincerely doubt that.
Rielly just needs the right partner. That does not mean he needs to be "sheltered", because he doesn't need to be sheltered. But he is also not a guy who is going to make a #7 look like a top pairing defenseman. If that is your expectation for a #1, then there are <10 in the NHL (and that is being fairly generous since none of those 10 guys actually have to do that with any kind of regularity).
Rielly with Brodie is easily a #1. Brodie is not a top pairing guy on his own but he compliments Rielly extremely well. Rielly with Holl or Liljegren is still pretty good as well. Liljegren has struggled a bit recently which makes it look a little bit worse than it did earlier in the season, but Rielly-Liljegren looked really good together when he was on. Rielly-Holl is either really good or really bad depending on how you want to look at it. As a pairing, I am fairly sure they are 1st in both GF/60 and GA/60. So if you need offense, there is nobody better. If you need defense, there is nobody worse.
When Rielly has had to play with Timmins, Gustafsson or Schenn, the pairing struggles. Rielly-Gustafsson just makes no sense given their play styles. Gustafsson is a pure offensive defenseman and Rielly is not the type to gel with that kind of guy. Schenn, like Lyubushkin, is not a top 6 caliber defenseman on any good NHL team so Rielly has to carry him. Timmins is just not ready for top pairing responsibility so he also needs to be carried, but looks fine as a bottom pairing guy.
Rielly with those three included in his numbers is around 70th in GA/60 and 100th in xGA/60 out of the top 140 defensemen in 5-on-5 ice time this year. Without those three, and he's only played about 10% of his total 5-on-5 ice time with them this year, his expected numbers jump up to the mid-60's and his actual numbers would be in the top 50... And these are his "defensive numbers", where everyone says he is a complete disaster. His offensive numbers would also jump but not nearly as much.
Or if you want another example of a small sample size killing him... In his first 5 games this year, he was on the ice for 8 5-on-5 goals against with an on-ice save percentage under .800. Some could be attributed partially to him, but he was on the ice for some really bad goals by his goaltender and some really bad turnovers by his teammates. His expectation in those games is better than his season as a whole, so those numbers go down if we exclude the sample, but his actual goals against totals? He goes from 2.5 GA/60 to 2.19 GA/60 without those 5 games (he has played 57 this year)... That is a huge jump.
Since the data is mutually exclusive (Timmins, Schenn, and Gustafsson were not on the team during the first 5 games of the Leafs' season), those two events account for <20% of Rielly's 5-on-5 ice time this year. Rielly in the other >80% of his season would have a GA/60 in the top 20 in the NHL, a GF/60 in the top 40, and expected numbers in the top 50 in the Shea Theodore and Miro Heiskanen range (Heiskanen also had far more offensive zone starts than Rielly to get those numbers; Theodore, slightly fewer).
Moral of the story: Rielly, when his numbers are not skewed by a really small sample of poor play by his teammates and he is not playing with our 7/8/9 defensemen, has played like a #1 defenseman... And what can really be considered a "down" year for him offensively, he is still on pace for 56 points in a full 82 game season while, in that >80% of the season, he has played the best defensive hockey in his career by far.
