Ok I haven't played since maybe nhl16? The whole line chemistry thing is very confusing to me.
If I have a 3rd line of Hoglander, Dickenson, Pearson, they are -1. If the same 3 guys are on line 4 they are +1. I've made sure the line strategies are all the same. I don't know what else to change.
It doesn't seem like a huge deal cause I can just use my 4th line as my 3rd line... but there's obviously something I'm not understanding and I'd like to make full use of the system.