What to expect when you’re expecting (goals)

Mar 21, 2023 - 3:30 PM

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If you delve into advanced stats or read PensBurgh much, you’ll probably notice that the Pittsburgh Penguins have a “finishing” problem this season. But what does that mean? Who are the players most letting down their end for turning chances into goals? Why is this happening?

Starting from the end, the why is the difficult part to solve. If it was known, the coaches and team’s skill director would have easily corrected issues and figured it out. Sometimes it can be luck, flukes, bad bounces, playing through injury, confidence that shrinks during a shooting slump that causes hesitation or a drop in performance and placement. Or, as it usually goes, some combination of many or all of the above. You name it. Hockey is a fickle sport where some games or stretches players can seemingly do no wrong, and everything they touch turns into a red light. Then at other times for no discernible reason, other long droughts can plague some the most talented players around.

The “what” is easier to define. Hockey data tracking has turned to embrace the concept of expected goals, if you’re new to the subject or topic there’s nothing wrong about it but you can read up and learn more here. Different public sources like Evolving Hockey, Natural Stat Trick and Moneypuck have seemingly slightly different formulas and determinations. NHL teams, it should be pointed out, do not use this exact data that fans pour over — most have private tools that are more refined like SportLogiq that give better information.

Anyways, you don’t need a mountain of data to know what your eyes tell you, especially lately. The Pittsburgh Penguins have the puck a lot, they shoot a lot, they haven’t been scoring much. The perfect illustration was last night, where Moneypuck tallied up the total Pittsburgh expected goals to be 4.05 due to the chances earned. They scored one actual goal on 49 shots. It’s enough to make one want to pull the hair out of their head and scream.

Overall, it can be tough to live up to the expected goal marks. Only 13 NHL teams currently have out-scored Moneypuck’s xGF for them in the 2022-23 season (where all data cited in this article has come from, unless otherwise noted). Yet, very few have been as frustrated as the Penguins. The Pens have scored 223 goals so far this season (other sites may say 224 by counting the game-deciding goal in the team’s lone shootout win). That’s 16th in the NHL.

Pittsburgh’s expected goals for in all situations is 252.4. That ranks 5th in the NHL for highest expectation, with a -29.4 “hole” of under-producing to expectation. This is atrociously poor and that -29.4 is the third lowest in the NHL (behind only Ottawa and Nashville). Overall, the Pens have shot just 9.3% this season, ranking 25th.

In short, that confirms what the eye test should be telling you: the Pens are producing a lot of chances, but struggling mightily and way more relative to the rest of the league than virtually everyone else at turning those chances into actual goals.

Who are some of the individuals adding or taking away from this frustration? Let’s take a look. (Note: Moneypuck has players’ whole seasons, so obviously players like Mikael Granlund or Nick Bonino did most of their work elsewhere that doesn’t tie 1:1 to the Pens’ season, but there is also useful information in charting what they’ve been up to in order to put into context their acquisitions).

This chart tells us that Bryan Rust has been struggling, Jeff Carter has lost it, and Marcus Pettersson is not good at scoring goals. None of this is breaking news. What stinks for the Pens is when you have important players all like Rust, Rickard Rakell and Jake Guentzel under-performing, that builds quickly to put the team in a hole. Also, if Mikael Granlund was the key part of your master plan to turn around the team’s fortunes AND bring on despite having term on his contract, it’s probably time to pack your stuff and leave.

On the flip side and positive: Kris Letang, Sidney Crosby, Jason Zucker and Evgeni Malkin have been reliably coming through for the team and doing their parts with putting the puck in the net. I also highly doubt any of this will be considered a shocking revelation.

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Now, let’s check on rates. Different players are meant to do different things, defensive defensemen who aren’t known for shooting the puck aren’t likely to out-score their expectations, or if they hit or miss, those expected amounts are small potatoes compared to the more offensive players. This next chart is sorted by Actual Goals per 60 minutes, to put a spotlight on the skilled players at the top of the lineup and see a rate of how players are generating expected goals versus actually scoring them.

The pattern is forming, you can point a finger at Rust and Carter as the biggest offenders or players who have let the team down the most this season when it’s come to finishing chances. Granlund isn’t far behind them. For as good of seasons as it feels like Rakell and Guentzel have had, they also could be scoring more (and in 2021-22 both of these wingers out-scored their expectations, this year they’ve lagged behind them).

Also, Jason Zucker’s actual goal/60 last year was 0.79, which is respectable enough but not terribly impressive. This year, it’s almost doubled to an eye-popping 1.39. Who can say what his future may hold next season and if he’ll perform more like 2021-22 or 2022-23, but what a magical and charmed year he’s been able to pull off right now. It’s a contract year, and he picked the perfect time to showcase himself with a tremendous season.

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Finally, the category of shooting talent stood out to me. Moneypuck defined it as:

now that some players are better shooters than others. By using bayesian statistics, we can estimate the shooting skill of snipers like Patrick Laine. The problem we are trying to solve is “What is the probability that a player is actually a certain shooting talent level given their performance in the NHL so far?”. As there is a lot of luck involved in whether a shot goes in the net or not, a player may get more or less goals over the course of a season than their true shooting talent would reflect.

So, in common terms, I suppose that means they’ve factored in that if Guentzel or Crosby takes a shot, there’s a lot more of a chance it will score than, say, Josh Archibald or Ryan Poehling. Didn’t see the data, and not holding this up as the Gospel, but the results were telling and made sense.

Everyone on the Pens — except four defensemen and Poehling — are under water here. And given the above mentioned 9.3% shooting%, that makes sense. Lots of players who have been good at scoring goals in the past are not as good at doing it right now, for whatever reason.

I think this chart and ranking answers the nagging question: “how can Guentzel already have a 30-goal season and it still somehow feel empty and underwhelming”? Well, this is why - it’s in essence saying “well, Guentzel averaged shooting 16.2% in the last four seasons, but that’s down to 14.1% this year”. Doesn’t sound like a big difference, but it adds up

As a common theme in this data, to wrap up some generalities of my key takeaways:

• Jeff Carter is bad at putting the puck in the net (among other things)
• Bryan Rust is somewhat quietly going through a very difficult goal-scoring season
• At this point of his playing career, Mikael Granlund was definitely not the player to hitch potentially one’s managerial career to
• The Pens are really fortunate that even at “old for hockey” or “past prime” ages that Crosby, Malkin and Letang have remained very strong at this very narrow focus of scoring goals
• Jason Zucker is having an amazing year
• Rickard Rakell and Jake Guentzel have done well, but could/should be scoring even more based on the amount of chances they’re getting (which makes sense giving the passing ability of players like Crosby and Malkin, which has not been the focus of this piece but also is true)

Overall, one of the stories of this season for Pittsburgh may be those frustrating games where they throw a lot of pucks on net, but fail to turn them into goals. Hopefully after seeing some of the data and the splits, it makes sense just who is struggling in this regard and why the team is at the juncture they are at when it comes to under-performing expectations.