The Chris Pronger Effect: Examining the Impact of Flyers' Captain's Absence

Those looking for a single moment when the Philadelphia Flyers’ status as a contending team came crashing down couldn't do a lot worse than October 24, 2011.

That was the night when Flyers’ captain Chris Pronger attempted to knock a puck off the stick of Mikhail Grabovski as the then-Leafs centre took a shot; the result was Grabovski’s stick catching Pronger in the eye on the follow-through to the shot.

Pronger missed two weeks due to the injury before coming back and playing five more games. He was hurt again—this time with a knee injury—and during his time off, it was discovered that Pronger had concussion symptoms.

He has not played since, and according to NHL.com, the concussion issues have subsided, but his eye injury remains a problem. Flyers general manager Paul Holmgren told The Hockey News' Ken Campbell in a recent interview that Pronger would never play again.

The Flyers have tried and failed to replace Pronger—most notably in the form of a 14-year, $110 million offer sheet to then-restricted free agent Shea Weber. They are simply not the same team without him, something that is borne out by the team’s collapse at even strength since Pronger’s departure.

Pronger’s impact on five-on-five situations can perhaps best be measured using Corsi—a statistic that combines shots, missed shots and blocked shots together to show which teams are controlling puck possession. Corsi tracks closely to time spent in the offensive zone, and both statistics have a high correlation with winning (something shown in a 2008 study at the blog Irreverent Oiler Fans).

With Pronger on the ice over his three seasons with the Flyers, Philadelphia out-Corsied the opposition 2,259-2,061.

In other words, 52.3 percent of all shots attempted with Pronger on the ice were being attempted by the Flyers. With Pronger off of the ice, Philadelphia was out-Corsied 8,376-8,316. Basically, without Pronger, the Flyers were a below-average NHL team in this department.

That number, however, understates the case, because a player like Chris Pronger generally plays against the other team’s best players.

His absence has caused a ripple effect on the team. Suddenly, a defenceman who is strong on the second pairing struggles in the first pairing role, and a player who is strong in a third pairing role struggles in a second pairing role.

That might explain why the Flyers’ Corsi numbers have collapsed. Since 2012, the team has been out-Corsied 2,486-2,269. With Pronger on the ice, the Flyers had taken 52.3 percent of all attempted shots to their opponents’ 47.7 percent.

Since then, the trend has reversed, with the Flyers taking only 47.7 percent of all shot attempts and the opposition taking 52.3 percent. The team is getting dominated to the same degree they used to dominate with Pronger. The problem is the fact that it's all of the time.

Of course, Pronger’s injury coincides closely with the departures of star players Mike Richards and Jeff Carter. Richards and Carter played a lot of minutes with Pronger, so it’s worth asking whether this collapse might have more to do with losing those two forwards than it does Pronger’s injury.

Player	w/ Pronger	w/o Pronger	Pronger w/o
Jeff Carter	53.0	51.1	52.1
Mike Richards	52.3	49.7	52.4

Based on available evidence, the answer to that question appears to be "no." Mike Richards’ on-ice numbers took a steep dive without Pronger, while Pronger’s totals were unchanged. Jeff Carter’s numbers away from Pronger are a little better. However, Pronger fares better without Carter than Carter does without Pronger.

This isn’t to say that the losses of Richards and Carter, as well as the other changes to Philadelphia’s lineup, have had no impact on their ability to win games. After all, it would be a real surprise if they did not have at least some impact.

In the end, the primary driver of the Flyers’ collapse appears to be the loss of Chris Pronger and the subsequent failure to replace him.