First you need to familiarize yourself with xGF%
Imagine if every shot that occurs on the ice has a value or rating. Dangerous shots have a higher value than less dangerous shots. By adding up the values of every shot on the ice, we get expected goals. We can then look at the expected goals of one team compared to the opponent to get expected goals for%.
Below are the 20 best lines in the NHL according to xGF%. This means that when these lines are on the ice, they are taking more shots and better quality shots than the opponent. They are then expected to outscore opponents when they are on the ice.
Below are the worst-20 lines in the NHL according to xGF%. When these lines are on the ice, opponents are taking more shots and the better quality shots. They are thus expected to do poorly when they play.
The Panik – Toews – Kane line is a league worst 29.66%. Lets round that up to 30% to make the following math easier. An expected goals for% of 30% indicates that when this line is on the ice, Chicago is expected to score 30% of all goals, while opponents are expected to score 70% of all goals. So if this line is on the ice for 10 total goals, one could expect those to be 3 goals for and 7 goals against.
The Panarin – Anisimov – Hossa line is the 16th best in the NHL with a xGF% of 62%. This means when they are on the ice, Chicago is expected to score 62% of all goals, while the opponent should only score 38% of all goals.