I pressed Alt + B while i was doing the subsurf tutorial and it was supposed to do select face loops, instead it just gave me a grey line on screen. i know in the tutorial their using an older blender version. i cant find the new face loop shortcut
Select Face Loop is alt-rmb in face select mode near the edge of the face that goes in the direction you want to attempt to loop. I haven’t been that sucessful in getting it to do what I want myself, but I’ve only tried once or twice too.