Vital Signs – Late October 2016 Edition

Every once in a while, I do a ‘vital signs’ analysis on the team.  I look at a variety of indicators that give us a look under the hood of how the team is doing on a number of important indicators.

Why do I call them important?

Because they tend to predict how well the team is going to do in the future much better than do the above the hood indicators like goals and win-loss record. The under the hood indicators tell us whether recent success (or failure) is likely to sustain.

Now that said, it is very early days, and so these numbers are going to shift around a lot (unstable condition, a symptom of life). Even so, they do carry a little bit of information right now, so the peek under the hood isn’t entirely futile. And it supports the idea of staying level headed – something that becomes all the more important when the team rockets off to the best start in many years!

The Vital Signs Monitor

To make the measures a little easier to review, I take my inspiration from the Star Trek vital signs monitor, to wit:

The main difference when using this idea for hockey is the switch in colour scheme. Unlike vital signs where normal is good and high or low is bad, with hockey the middle tends to be good (for a middle pack team), the high numbers are often unsustainable, and the bad numbers you hope will rebound. So we adjust.

Let’s see how that looks for Our Oilers (click to embiggen; data from corsica.hockey):

Down below, I explain the rationale for the indicators I’ve used.  If you’re not interested in such arcanery, just pay attention to the rankings for overall, EV offense, EV defense, special teams, and what I call ‘unpredictables’ (sh% and sv%, which are volatile and for most teams without either elite or terrible goaltending tend to move strongly towards the midline as the season progresses).

What’s the Frequency, Neal?

First, before we mull on this chart specifically, take a minute to think on what you think the chart should say by the end of the year. Are the Oilers a top 10, middle 10, or bottom 10 team?

In my view, there are some terrific strengths (McDavid, C depth, the new top pair) married to some real flaws (backup goalie, right wing depth, not enough righties on defense). I’d call this a mid pack team – I don’t expect the current record to sustain, but I don’t expect a fall all the way back to historic depths either.

IMO

In that context, this vital signs set actually looks OK to me.

• Sh% is high and will likely come back to earth.
• Sv%? Well, it’s not out of the question that the Oilers have a Top 10 goalie if Talbot stays healthy.
• The PP shot rates give me great cheer. These are excellent numbers, and exactly what you’d hope to see a team loaded at forward able to do. Huzzah!
• The PK shot rates cause some concern, and that SA60 number needs to come up big time.
• The EV CF% is not very good, but most of that is the poor shot rates against. Some of that is score effects, as the Oilers have opened up the score a few times. But it is concerning. Like a few others, we’d like to see it move up towards the middle as the season progresses.
• The xGF numbers are higher than the CF numbers. Both have comparable predictivity, so I’d expect the two of them to converge in the middle. And middle is good.  By the way, in December of last year the trend was reversed – the Oilers were having trouble converting their shots to dangerous chances, so this is not a bad place to be.

Bottom Line

I’m usually quite curmudgeonly when I look at the Oilers fancystats.  They haven’t been good over most of the last decade – and they’ve been right.

This year, though, I’m a little encouraged. Overall, this is kind of where the Oilers should be if they are to be a middle tier team.  As long as the raw shot metrics (CF/CA) move towards the danger metrics (xG) and stay somewhere in that middle lane, life is good.  We’ll keep our eyes peeled.

But there’s a bright side to the great start, even if it’s unsustainable. Because the early points are banked, they can’t take them away, and other teams have ridden an early hot streak and late season mid-tier play to a playoff berth.

So why not us?

Happy i.e. Ungloomy Halloween!

Addendum – Metrics Rationale

Ferda boys.  Ferda!

I use these metrics, for the following reasons.

1 – CF% (5v5 Corsi For %) is the single best predictor of future success we have (it’s not great, but it’s as good as we’ve got).  I break the components of this down into rates to look at the offense and defense separately.

2 – I roll in the corsica.hockey expected goals (xG) to get a sense of whether the shot attempts levels that Corsi is giving us are translating into dangerous chances.  Again, also looking at offense and defense rates broken down.

3 – I look at shot rates on the special teams. I don’t use Corsi in this case, because I’m not interested in possession so much – the team on the powerplay should have possession as a given! Rather, I look at how many unblocked shots the team gets on net (or gives up). This is a sustainable skill on powerplays.  I add in the expected goals, again to incorporate the degree of danger for and against.

4 – Just for fun, throw in the shooting and save percentages. These don’t tend to stick or predict very well, but usually if they are unusually high or low, you can expect them to move back towards the middle as the season progresses.