It seems that sports with many different dimensions and factors involved are easier to beat than those with few. I'm sorry but it just seems to me that a sport like the NHL is very static when it comes to betting.
-The goalies are always in the same form. Sure, they are less effective vs. better teams but that's already incorporated into the line.
-the players are much the same as goalies. Their skill level in any given game is going to vary little to none whereas baseball players can be on streaks, slumps, and everywhere in between and have their games very much impacted by the pitchers they face.
I guess I don't know where I wanted to go with this but feel free to discuss some handicapping theory itt.
I mean I agree with you that if a sport is very simple to model there is less chance for inaccurate modelling, but there are other things that make a market easier to beat than just bad modelling by the bookie