Here's the really broken thing with fumbles. They are determined on a percentage chance per play and the Avoid Fumble rating only has a minimal effect of _preventing_ the player from fumbling. This means the following:
1) Avoid Fumble doesn't actually tell you how good a player's hands are, and you can more or less ignore it for most positions.
2) There will be more fumbles in 0.4.4-0.4.5 because it takes MORE PLAYS to score which means MORE CHANCES for fumbles (that aren't really negated by a high Avoid Fumble skill).
It is one of the MOST annoying things about the game right now because it exposes one of the logical problems with how the game is currently written where attributes don't actually determine ability, but only provide a _chance_ to negate something imposed by the game.