Rasmus Ristolainen is one of the most divisive players in hockey. The Numbers and The Eye Test can't agree on what he is, so here is a closer look at Buffalo's presumed No. 1 defenseman.

The biggest debates in hockey these days usually come from two opposing viewpoints of how best to analyze the game: the numbers vs. the eye test. The two groups are usually on the same page, but there are times when they’re worlds apart, and that’s usually when evaluations get interesting.

It’s in those instances where things are especially illuminating. Maybe there’s something missing from the equation or maybe there’s an aspect that goes unnoticed, but what’s usually clear is that neither side is perfectly right and there’s a place somewhere in the middle (or closer to a specific side) to co-exist. Current hockey data is primitive and the sport is so fast and dynamic that there’s bound to be things missed on both sides.

That brings up the curious case of Buffalo Sabres defenseman Rasmus Ristolainen, who is probably one of the most divisive players in hockey right now. At least, among those two groups from above. The soon to be 23-year-old was picked eighth overall in 2013 with the hopes that he would blossom into a No. 1 defender, a vital piece to a rebuilding team.

There are people who believe Ristolainen is already there, if not very close, and others who see someone who belongs much lower on the depth chart. I conducted a quick Twitter poll to see what people thought and while most people said second pair, the difference between that (47 percent) and top pair (39 percent) wasn’t too large, with some suggesting he might be even worse.

This poll isn’t very scientific and has the bias of my followers (who are probably also numbers nerds) engrained into it, but the results are interesting in showing the divide in opinion of what Ristolainen is at this point.

I understand why people see him as a top pair defenseman. His 45 points last season, 15th among defensemen, is nothing to sneeze at and neither is his monstrous 26:28 of ice-time per game. Only four other guys saw the ice more than Ristolainen did last season and not many other defenders saw the level of competition he did either. Then there’s the fact he was the quarterback of an elite power play that finished first in the league last season. Pretty impressive for a defenseman his age.

He's being used in big, important minutes and he’s producing in them, so how is he not at least a top pair defenseman?

For starters, his point totals are a little deceiving. Sure, 45 points is nice, but it’s a lot easier when you’re getting as many minutes as he is. To his credit, he definitely was an elite power-play producer last season with a 5.61 points-per-60 rate, the sixth best mark among defensemen, but his scoring is nowhere near as prolific at 5-on-5. There he’s at 0.64 points-per-60, sandwiched between Marco Scandella and Ben Chiarot and good for 128th in the league, or third pair company.

Elite powerplay QB, but third pair scoring at evens, and you can see why some people were splitting the difference and marking him as a second pair guy. The season before was a similar story though he was a bit better at 5-on-5 and a bit worse on the power play. Either way, you got a 40 to 45 point defenseman that’s doing the bulk of his damage on the power play while being mostly ineffective at creating offense when both teams have the same number of players.

There’s more to his 5-on-5 struggles, too. Points are nice, but top defensemen usually need to drive play. Ristolainen doesn’t. So much so that he’s actually one of the league’s worst defenders in that regard. Over the last two seasons, Buffalo has taken 44.8 percent of the shot attempts when Ristolainen was on the ice, which is 4.4 percent worse than when he’s on the bench.

Of the 236 defensemen to play 41 or more games in that time span, only 20 have worse relative numbers. I’ll even name them so you can see the company he’s in.

Brandon Carlo, Derek Forbort, Tom Gilbert, Jyrki Jokipakka, Kris Russell, Deryk Engelland, Andrew MacDonald, Cody Ceci, Kevin Bieksa, Matt Tennyson, Karl Alzner, Rob Scuderi, Korbinian Holzer, Nick Schultz, Mark Stuart, Nicklas Grossmann, Matt Carle, Anthony Bitetto, Dan Girardi, Willie Mitchell.

There are exactly zero top pairing defensemen on that list (Sorry, Montreal). In fact, there are probably more players who are out of the league now than there are second pairing guys here. And that’s the main crux of why Ristolainen is so reviled around many analytics circles: when he’s on the ice, the Sabres get killed. Most of that is on the defensive side where the Sabres have given up about nine more attempts per 60 with Ristolainen on the ice.

Now there is a caveat to that and it’s part of the Top Pair Ristolainen Argument: he does play tougher competition and he also plays with weaker teammates. Ristolainen is being put in a very tough situation without much help around him.

The effect itself is hard to extract, but I’ve got a method using 5-on-5 Game Score. Ristolainen faced forward comp in the 95th percentile in both of the last two seasons, which equates to a Game Score roughly 0.05 higher than average. It’s not much, but it’s basically equal to the effect it had on him. Over the last two seasons his 5-on-5 Game Score is -0.14, but after accounting for usage (including his teammates) that number should be closer to -0.07. That’s still below average, but it’s closer to break-even than before and puts him at the high end of third pair territory at evens. Usage matters, but a guy who does poorly is usually still a guy doing poorly even after accounting for it.

The big question from this now is why his numbers at 5-on-5 stink, because it’s not just who he faces or who he plays with. The NHL doesn’t really track numbers that tell us any answers in that regard, but dedicated hobbyists do. One of the big findings from the last few years is that carrying the puck over the line instead of dumping and chasing led to more than twice as many shot attempts. Defenders who allow a lot of shots, like Ristolainen, tend to give up the blueline more.

The man who tracked zone entries for every game of the 2013-14 season, Corey Sznajder, was back at it again last season (though this time around there are only partial season stats) and the numbers aren’t pretty for Ristolainen. Compared to every team’s No. 1 D-man and the few others who were top 30 in TOI, Ristolainen looks more like a traffic cone than a traffic cop in defending Buffalo’s blueline. Just three defenders allow carry-ins at a higher rate than Ristolainen and it’s the same story for breaking up plays at the blueline.

That’s not to say the order of this list means best or worst defender, it’s just best or worst at this specific skill – one that correlates highly with allowing a lot of attempts. It’s a likely reason why Buffalo bleeds shots against when Ristolainen is on the ice, he’s way too passive at the line and doesn’t break up many plays compared to the league’s top defensemen. (He’s below average compared to regular defensemen, too).

Interestingly, one of the league’s best shot suppressors, Mattias Ekholm, is right below him. To get such different results means there’s something Ekholm does better in the defensive zone or he defends fewer entries (or maybe being paired with the guy at the top of the list), but it also means this might not be the only reason Ristolainen struggles.

On top of allowing anyone and everyone into the Buffalo zone, Ristolainen also struggles to get it out with control. The best breakouts come from skating or passing the puck out, and Ristolainen only manages that in 42.6 percent of his successful breakouts, the worst mark among these top defensemen. Almost every other defender here gets it done at least half the time. Two-thirds of Ristolainen’s exits are either dump-outs, failed attempts, or icings – all of which usually lead to a regroup back into Buffalo territory.

So Ristolainen lets anyone into the zone and doesn’t really do well at getting it out afterward. That pretty much explains it… probably. It seems pretty cut and dry with Ristolainen, but seeing Ekholm right there with him again is strange given they have polar opposite results. There’s more to be uncovered there and it may be the key to turning around Ristolainen’s game at 5-on-5, but for now it’s a pretty simple diagnosis: safe is death.

I think that might be one of the big reasons those that watch Ristolainen are enamoured by his play – there’s not much risk involved in what he does. In transition defense he defends and protects the net, not forcing anything at the blueline, backing in and allowing opposing forwards free reign into the zone, but guarding the net front. Going the other way, he usually goes for the safe play out of the zone, without much care for how it gets out. These are traditionally low-risk plays, but they come at a much higher price than other options, even if it doesn’t seem that way. It usually means a lack of or loss of possession and Ristolainen’s results attest to that.

All this is fixable though, especially with a new coaching staff. It’s possible that this style of play had more to do with what Dan Bylsma wanted than Ristolainen’s ability. He’s still very young, his peak years are ahead of him, and they may be much better than what he’s shown so far.

They’ll have to be if Buffalo intends to contend. He’s their No. 1 guy, but he’s not a No. 1 on a good or great team. That’s the sentiment I got from a quick survey around the THN office who likened him to a 2D or second pairing guy on a good team in his current state, and it’s the sentiment I got from the Twitter poll from above. By the numbers he’s a strange case where he looks woefully in-over-his-head at 5-on-5 yet magnificent on the power play. Split the difference and that puts him probably around the second pairing. By Game Score that’s exactly where he is, too. He’s Buffalo’s top D-man, but on a good team he wouldn’t be and that’s a big reason why Buffalo isn’t a good team.

Sabres fans may not like it, but it’s hard to see it any other way. Ristolainen may be a top defenseman in the league soon, maybe even next year, but he probably isn’t one now.

Data via hockey-reference.com, naturalstattrick.com, nhl.com, theenergyline.wordpress.com