Which attribute effects player's reliablilty?

I have Dominic Craddock, age 21, incredible attributes overall, but he is so unreliable. One match he crashes the opponent with 4-5 goals, next match he end up with only 5 or 6 rating no goals or assists at all.

On the other hand, I have Lewis Grabban, age 26, attributes are not as good as Craddock, but he rules. He is 2nd best scorer, 2nd best rated player in EPL for 2 seasons. He always performs good, in every match.

Why? Is it age? Personality? Some mental attributes?

Consistancy, mostly. It's hidden, for obvious reasons. Stamina could also do this, as a player may be tired in some matches.

If the manager works with his player most days and gets to know him he will have a good understanding of his consistency so i don't think it should be hidden.

Well not really, you can just work it out by looking at their form though.

I dont know. I like the fact its hidden, you need to learn about a player to know he is consistant or not as part of the fun of making a team.

If you can see consistancy, you'd make a super team of amazing ultra consistant players and pretty much never lose or have variable results.

Boring really.