Better let all the sports statisticians know they need to find a new job

Do they look at exactly one number and decide exclusively upon that number?

No, but there are numbers that many people would consider more important than the others. And if skill is 'not numerically identifiable' than it doesn't matter how many numbers you throw at it, they won't show any skill, which was the point I was making in my response, skill is definitely identifiable by numbers, but what numbers truly identify skill are a matter of opinion. In reality it takes several different stats, not just one. Anyone who thinks that one number is a tell all factor of skill is fooling themselves

That's the general gist of what I'm trying to say. Although I personally believe that even a culmination of numbers can only give a general identifier of "skill".

Someone else pretty much said it perfectly earlier in this thread. Statistics can give a general idea of skill, but to really figure out a person's true skill you need to have a field test. I agree with that, most if not all statistics can be padded or fabricated to make something look better than it truly is, but a field test will remove all doubt