The trade that never occurred involving Rasmus Ristolainen was one of the main topics heading into the 2019-20 season. The Buffalo analytics community lamented the loss of what was perhaps the last, best chance to acquire significant forward help in return for the then 24-year-old. His most ardent defenders however, expressed excitement about a possible elevation of his game under first-year head coach, Ralph Krueger.

With the remainder of the season presumably cancelled (for the Sabres at least), it’s time to review his performance, and determine if he truly made measurable improvements in a defensively conscious system. In order to get a clear picture, we’ll dive into his overall usage, defensive partners, and year-over-year impacts for comparison sake.

Let’s first get the data in front of us, and see how his relative metrics held up compared to 2018-19. Then, we’ll dive a little deeper and try to apply the necessary context behind the data. On the surface, Ristolainen’s relative Corsi, and xG numbers both took a significant hit this season. In Phil Housley’s final year behind the bench, Ristolainen’s marks in those categories were -2.78, and -.15, respectively. Interestingly enough, his xG ratio from last season was the second-best of his career (which obviously isn’t saying very much).

This season, both categories were markedly worse. He registered a career-low relative Corsi of -4.71-percent, and a career-low expected-goals percentage of -3.72 at five-on-five. At face value, that looks really bad, but was his actual performance truly reflective of the year-over-year deltas we’re seeing, and did the Sabres’ coaching staff do enough to revise his role?

For as much as talented defensive partners tend to elevate the performance of their pairing mates, the reverse effect can also take place. In 2019-20, Ristolainen had two primary defensive partners, logging 508:19 with Jake McCabe, and 334:13 with Brandon Montour. His third-most consistent partner was Lawrence Pilut, with whom he skated for a mere 96 minutes.

Unsurprisingly, his best metrics came during his time with McCabe, a player who, despite having many of his own flaws, possesses a complementary skill set to what Ristolainen brings. The WOWY (with and without) numbers are helpful indicators as to which partner was carrying the load for the pairing. For Ristolainen and McCabe, a duo that accounted for positive relative Corsi and xG marks of .33-percent, and 3.79-percent respectively, the deltas paint an interesting picture.

Away from Ristolainen (a total five-on-five time of 537:42 on the year, which is essentially equal to his aforementioned TOI with him), McCabe’s relative Corsi shot up by 2.26-percent, while his relative xG actually experienced about a one-percent reduction. Conversely, Ristolainen had much less success sans McCabe.

In fact, his relative Corsi absolutely plummeted down to -5.97-percent, and his xG mark experienced over a 10-percent decrease. This disparity is potentially indicative of who truly benefitted more from the pairing, but it’s probably not to such a dramatic extent. While Ristolainen’s numbers away from McCabe are truly ghastly, it’s important to consider who he was alternatively paired alongside.

Enter Montour, whose skill set is about as non-complimentary of RIstolainen’s ( every other defender on the Buffalo roster) as you can imagine. While Montour’s above-average acumen as a zone-exit and entry entity is certainly something Ristolainen doesn’t possess, neither of them are particularly adept defensively. As a tandem, they accounted for a relative Corsi of -7.25-percent, and an xG of -8.33. In both categories, Ristolainen and Montour produced comparatively better away from one another, which begs the question – why did Krueger play them as a pairing with such frequency?

So, what’s the conclusion here? Obviously Montour was a bad fit for Ristolainen, and their time together accounted in large part to the aforementioned career-lows that Ristolainen produced from an advanced stats perspective. The truth is likely somewhere in between.

Circling back to the offseason narrative about Krueger being able to optimize him; it’s very clear that assertion turned out to be false. While he did manage to reduce the Finnish workhorse’s ice time by a full minute at even-strength, he did an abysmal job of optimizing his skill set in just about every other demonstrable way. Despite knowing full well that Ristolainen’s most glaring shortcoming comes as a result of his penchant for firing the puck along the boards instead of using his vision to facilitate a counter-rush, Krueger’s decision to deploy him in a similar defensively tilted ratio as Housley did, is rather mind-blowing.

The above chart fortifies what our eyes have told us about him as a player. The zone-exit and entry metrics are very weak, while his ability in the offensive zone is quite strong. Logically, a player like that should be deployed in an offensively slanted manner. Alongside McCabe, Ristolainen’s OZS rate of 44.22-percent can be partially forgiven, considering McCabe’s best attributes are his above-average defensive metrics. The question then becomes, how do you balance those complementary styles with proper zone deployment? Likely, better results would have manifested with a more balanced approach (and if Krueger had kept Ristolainen away from Montour entirely).

Overall, the Sabres defense displayed improvement from last season. That point isn’t really up for debate. While some spectators mistake Ristolainen’s physical prowess for defensive competence, the shot data (and basically every other metric for that matter) tells a different story. As a group, the Buffalo blueliners allowed a perfectly average amount of shots-against this season. With Ristolainen on the ice however, they allowed five-percent more unblocked attempts over-average.

Offensively, the contrast was just as stark. As a team, the Sabres registered nine-percent fewer unblocked shots-for per 60 minutes than the league average. That number drops an additional six-percent when the 25-year-old was skating. Some might mistake that for offensive ineptitude, but the truth is, the two metrics sort of go hand-in-hand.

When a defenseman struggles to exit the zone, there is a related effect as it pertains to chances-for. If that player isn’t helping facilitate a counter-rush (while subsequently being hemmed in their own zone as a result of his failures to clear the puck, even along the boards), then chances-against will obviously go up, while chances-for go down. This problem is exacerbated to an extent when that entity is being asked to play heavily defensive minutes. On top of that, Ristolainen played the most minutes (despite a modest five-on-five reduction, he was still the Sabres’ defensive ice time leader by more than three minutes per game), against top competition, the negative effect of which, takes on an even greater presence.

The analytics community has begged the Sabres to try and put Ristolainen in a more sheltered, offensively tilted usage pattern. His continued analytical trends do everything but scream for the coaching staff to ask less of him defensively, but alas, the approach remains the same.

So, did Ristolainen actually get worse this season? Probably not – at least not to the extent the metrics would indicate at face-value. He certainly didn’t improve in any discernable way, but again, as demonstrated above, Krueger is now the fourth consecutive Sabres bench boss to utilize him in a sub-optimal manner. His approach to getting the most from Ristolainen was just as bad, if not worse than Housley’s, which is saying something.

Naturally, these findings inspire questions about his current trade value, and to what extent Jason Botterill missed the boat by refusing to part with him last summer. Fortunately for him, the one thing that might help in that regard, is good old fashioned point production. Though his power-play minutes saw a significant reduction in 2019-20, nearly 38-percent of Ristolainen’s even-strength minutes were spent with Jack Eichel and the Sabres’ top scoring line. By association, his base statistical production saw only a minor reduction as a result.

While Ristolainen’s mark of .478 points-per-game was the lowest since his rookie season in Buffalo, there are general managers across the league who would still likely pay a decent price for it. It may not be the same return the Sabres would have received a year ago, but the value isn’t completely gone. Whether or not Botterill intends to pull the trigger instead of jamming this square peg into a round hole for a seventh-consecutive season, remains to be seen.

TOI, Zone Deployment, Corsi, and xG metrics, courtesy of Natural Stat Trick

Exit/Entry, xG Ranking, and Defensive Pairing charts courtesy of Charting Hockey

Shot Heatmaps courtesy of Hockeyviz