How important is connection quality?

I was wondering, if you had to guess, what percentage of a chance does s.o with superior connection have of winning? Obviously I'm talking about similar skill level but at times it's difficult to evaluate whether it's a skill issue or not, from players reacting slowly, badly positioned, lamine going from silky smooth to unable to dribble past anyone, penalties saved as if the direction is known before hand, opposite defenders just staying still and your player gravitatimg towards them.

So, is it real or juat an excuse we like to use?