You could just explain goalkeepers though.

They need to have many attributes, all of which could be marked out of 10.

Shot-stopping.
Catching crosses.
Punching crosses.
Parrying the ball out of danger areas.
One on ones.
Penalty saving.
Dead ball kicking.
Dealing with back passes.
Lumping the ball forward.
Communication with defenders.
Rolling the ball under your studs whilst thinking about what to do.
And many more.

I'm sure that Hinchliffe would be judged higher than Addai on a few of those and vice versa.

Also, adding the scores up doesn't necessarily mean that the one with the highest score is the better goalkeeper.

It's a complex job and I'm glad that we've got two decent goalkeepers to choose from.

I'm also glad it's not my decision. 🤣