The Hagg MacDonald Pairing
Despite a recent trajectory that has them moving toward a playoff position, the Philadelphia Flyers have a significant problem with the defensive pairing of Robert Hagg and Andrew MacDonald. Below, we show that the poor performance of this pairing has been largely masked by luck and that the future goal differential with this pairing on the ice is expected to crater.
Player Usage Chart
We begin by examining the Player Usage Chart for the Philadelphia Flyers. We publish these charts for all NHL teams on a nightly basis. At their core, these charts demonstrate two ideas: (1) how players are being used by their coach (represented by bubble size and location) and (2) how effective players are in these roles (represented by bubble color).
The Player Usage chart reveals that the Hagg-MacDonald pairing is on the ice for difficult minutes. Their vertical position (above the midpoint) suggests that they are on the ice against tough competition. Their horizontal position (to the left of the midpoint) suggests that they start the majority of their shifts in the defensive zone. The bubble sizes tell us how much time these players spend on the ice. In this case, the sizes are consistent with being a second pairing. The fact that their bubbles are dark blue indicates that the team is being heavily outshot while this pair is on the ice.
Possession and Luck Chart
Another tool we can use to examine the Hagg-MacDonald pairing is the Possession and Luck Chart for the Philadelphia Flyers. The Possession and Luck Charts (Pluck) combine shot and goal data into one easy-to-read chart.
The horizontal position of the bubble is an indication of whether or not the team is being outshot while this player is on the ice. The vertical position of the bubble compares the SHSV% value of a player to the league average. A player with a significantly high (low) position on the chart is getting lucky (unlucky). The bubble size measures the team shooting percentage while this player is on the ice, while the bubble color measures the team save percentage while this player is on the ice.
This chart reveals that the SHSV% value for Hagg and MacDonald is significantly above 1000. That means this pairing is on the receiving end of good luck during even-strength situations. The bubble size (EVSH%) and bubble color (EVSV%) tell us what kind of luck. In the case of Hagg-MacDonald, their bubbles are dark orange indicating that the team has a very high save percentage while these two are on the ice. To make this very clear: the dark orange color suggests that the Philadelphia goalies stop more shots from going into the net when Hagg and MacDonald are on the ice together.
Putting It All Together
We learned from the Player Usage Chart that the Hagg-MacDonald pairing logs significant ice time and that the team is heavily outshot while these two are on the ice. We learned from the Possession and Luck Chart that the Hagg-MacDonald pairing has been on the ice when the Philadelphia goalies are posting their highest save percentages. Our interpretation of this data is that the poor play of the Hagg-MacDonald pairing is being masked by luck. Eventually, the abnormally high save percentages should drop and the team will start to bleed goals at even-strength with this defensive pairing on the ice.
These changes should be noticeable on the Possession and Luck Chart by the end of the season. The Hagg and MacDonald bubble colors should trend from their current orange color toward the direction of blue. Additionally, the often maligned statistic of +/- should drop in the coming weeks for both players. At the time of this writing, Hagg is +13 and MacDonald is +7.