In Brother's Little Helper, episode No. 228 of "The Simpsons," Marge and Homer are called to the school for a meeting with Principal Skinner regarding their son, Bart.
"Your son is a ravenous demon, relentlessly gnawing at all that's good and true," said Skinner. "... But worst of all, he drags down the grades of anyone who sits near him."
Skinner pulls out a chart illustrating the effect:
Skinner then brings out a 3-D map, showing what he calls "an unmistakable cone of ignorance":
Marge, horrified at the visual, tells Skinner to put the cone away, but Skinner says there's no escaping the truth, and diagnoses Bart with ADHD.
At this point, you're probably asking, "Taylor, what the heck does this episode of 'The Simpsons' have to do with Jack Johnson?"
Just as Bart brings down the grades of those sitting around him, Johnson brings down the stats of those on the ice with him.
Corsi measures shot attempt differential (shots on goal, missed shots, and shots that are blocked) while a player is on the ice during five-on-five play. A Corsi For percentage (or CF%) of 50 means the player's team faces just as many shot attempts as their team attempts while the player is on the ice. Anything over 50 percent is good, since it means the team attempts more shots than they face.
Using Natural Stat Trick, we can see a player's CF% both with and without Johnson on the ice. In nearly every case, a player's CF% drops with Johnson on the ice:
What about his defense partner, Marcus Pettersson? Is he off the hook?
The eye test shows that Pettersson has been underperforming of late, too, but the trends statistically aren't quite as drastic as with Johnson. Of current Penguins who have played at least 30 minutes with Pettersson, only Bryan Rust, Garrett Wilson, Jake Guentzel, and Sidney Crosby have a higher CF% without Pettersson than with him. Corsi For is an on-ice metric, not an individual metric, so when Johnson and Pettersson are on the ice together, they record identical numbers. The time this season when they have been apart has made a difference.
We can also point out Pettersson's numbers with and without Johnson. Pettersson's CF% with Johnson is 48.42. Pettersson's CF% without Johnson is 50. Johnson's CF% without Pettersson is 34.73.
Corsi isn't a perfect stat, but on-ice shot attempt differential is a pretty important metric.
Given that Johnson is a defenseman, and a shot blocked by the Penguins still counts as a Corsi against, we can also look at Fenwick. Fenwick is the same as Corsi, with blocked shots taken out of the equation.
When we look at Fenwick, we see the same trends. Only Evgeni Malkin and Tanner Pearson have a better Fenwick For percentage with Johnson on the ice than they do without him on the ice.
Johnson does lead the team in hits, with 156, and is second in blocked shots, with 97. That has to be taken into consideration. But hits and blocked shots can also be misleading stats. If a player is laying a hit or blocking a shot, it means his team doesn't possess the puck in that moment. And as seen in the numbers above, opposing teams are possessing the puck and are afforded a lot of chances when Johnson is on the ice.
It's also worth noting that Johnson starts in the defensive zone the least often of the three zones. He's had 100 defensive zone starts (fourth among Penguins defensemen) this season in five-on-five play. He's had 101 offensive zone starts (fourth among Penguins defensemen), and 171 neutral zone starts (third among Penguins defensemen). Johnson isn't on the ice for a high number of total defensive zone faceoffs, either -- 240 -- fourth among Penguins defensemen. So it isn't that he just happens to find himself starting out in the Penguins' own zone more often than other defensemen.
In "The Simpsons," Ms. Krabappel probably could have just minimized Bart's impact by sticking him in the corner of the seating chart. The answer for Johnson isn't quite that simple. He's already on the third pairing now, and a trade would be next to impossible. When Justin Schultz returns, perhaps Johnson will have a better shot in the new pairings, playing on his natural side of the ice.
For now, there's an unmistakable cone of inadequacy.
