For the majority of this season, the Buffalo Sabres were one of the top shot suppression teams in the NHL. They were in the top 10 in the league in shot quality against (xGA/60) and shot attempts against (CA/60) at 5 on 5.

That was one of the areas that fans and the team could point to as an area of improvement this year. If they had some offense to go along with that, maybe they would have found themselves higher in the standings when the season was suspended.

However, a tweet the other day from Sean Tierney caught my attention and sent me on this journey I’m writing about.

xG rates – last ~10 games before the pause

ARI was creating the NHL’s most quality for, which I didn’t realize.

TOR had settled into dull, also strange.

WPG was finally creating (but still allowing the NHL’s most xG against).

VGK and MTL, together forever at the top. pic.twitter.com/uVKRPfiaFA

— Sean Tierney (@ChartingHockey) April 12, 2020

Over the last 10 games of the season, the Sabres were one of the worst teams in the league in shot quality against. A far cry from what they were the majority of the season. Their numbers were closer to league average over the last 25 games of the season in shot quality against.

Hypothesis Confirmed

I wanted to find out why this was the case. Why did the Sabres defense get worse over the last quarter of the season?

Going into this I had a theory on one of the primary reasons, but I wanted to check all avenues. The Sabres had some injuries to key players like Jeff Skinner and Victor Olofsson that impacted the team, but I doubt it would have affected the defense. Olofsson was arguably one of the worst defensive forwards on the team and Skinner isn’t known for his defensive game either.

Jack Eichel’s line had some struggles near the end of the season, but it was only over the last few weeks. His usage didn’t change and he didn’t have a much of drop in his shot quality against metrics over the last quarter of the season. No other player on the roster saw a significant change in their usage and deployment besides two players. Those two players were Rasmus Ristolainen and Brandon Montour

They were deployed as the top pair for the Sabres over the last two months of the season. To say it didn’t go well may have been an understatement. Thus that pairing was my working theory going into this exercise that they were one of the primary reasons for the drop in defensive performance and it was confirmed.

Kruger’s Mistake

As I started to dig deeper into this pairing I started to realize that while Ristolainen and Montour are responsible for their performance; another person may carry more of the blame here. That individual is Ralph Krueger.

Let’s go back to early in the season. Kruger utilized Ristolainen and Montour in November and December as a pair that played late in the game in situations where the Sabres were tied or trailing. It was working and I even wrote about it for Die By The Blade.

In that situation, they weren’t forced to focus on defensive play as the opponent was sitting back looking to get to overtime or defending a lead. On a side note, I recommend checking out this presentation from Micah McCurdy on score effects from the Columbus Analytics Conference in February to get a deeper understanding of what I’m referencing.

As you can see on the chart above, all of a sudden Kruger changed his approach with the pair in January. They went from above 75% of their time on ice percentage in situations where the game was tied or trailing, to neutral usage from January on.

I can understand if Krueger wanted to see if the pair had the potential to play a more impactful role throughout the game because of their success early in the season. However, the chart below will show you where things start to take a twist.

I brought shot quality against (xGA/60) at 5 on 5 into the picture above. As you can see, November and December were good at their particular usage. Then in January things went bad in a hurry with the new deployment as I mentioned above. This should have been a red flag to Krueger and his staff that giving this pair anything but situational minutes late in games was a bad idea.

Yet, Krueger decided to double down on this pair and play them as the top pair over the next two months in neutral usage again. Of course, the corresponding results were bad from this decision. If you’re wondering if the offensive output perhaps outweighed the defensive results, the answer is no. Here are the on-ice shot quality for (xGF/60) numbers by month at 5 on 5:

• Nov: 3.01
• Dec: 1.64
• Jan: 0.92
• Feb: 1.96
• Mar: 1.56

When you line up the team’s month over month shot quality against at 5 on 5 you’ll notice a correlation when things start to head in the wrong direction in the chart below.

As I mentioned, for the majority of the season they were below the league average (that’s good) in suppression, but things started to head in the wrong direction when the pairing of Ristolainen and Montour was given a bigger role with the club. They finished March above league average and were one of the worst teams in shot quality defense in the last 10 games as Sean pointed out.

Conclusion

It was mind-numbing to see that pair rolled out night after night to get dominated by the opponent. The important western road trip after the deadline was the peak of that pairing failing the team.

Krueger holds responsibility for allowing this to go on as long as it did. Even if the didn’t have the data to back up what was happening, the eye-test alone should have told him that it wasn’t working.

The Sabres may not have been able to get back in the playoff race, but their head coach held them back from doing so with this decision. Unfortunately, this has been a trend with the team over the last few years with the coaching in Buffalo. When you have a roster of limited talent, it can’t be hampered by poor coaching decisions if they want to have any chance at success.

Data via Evolving Hockey, Natural Stat Trick, and Charting Hockey