Consistency
From MLB Power Pros Wiki
"In Game Description Here"
Description
The blue ability, Consistency, gives a very vague explanation of "Not streaky", which to this author seems more like a batters ability than a fielders. Consistency may mean one is not as prone to being good on one at-bat and bad at the next, but consistently one trait, whether it be bad or good. In any case, consistency is a good value to obtain, even if one is consistently bad, at least you can rely on that.
The blue pitchers ability, Consistency, also says "Not streaky", but in this case it's more understandable. When a pitcher becomes predictable it's much easier to hit off of him, but one can be consistently changing his pitches. In the case of pitchers, you don't want them to be streaky as it's unpredictable how each pitch will come out, so becoming consistent is quite important to pitchers.
