A win is a win. You don't get style points for blowing out the other team. They can won by one every week for all I care, even if my body can't take it.http://www.footballperspective.com/the-definitive-analysis-of-offensive-fumbles/
This breaks down the type of fumble and the recovery odds per fumble. Forcing fumbles is a skill. Recovering fumbles is mostly random.
Your team has been getting very lucky in winning all these close games. That luck will turn eventually. People said SF's close game luck would turn, and maybe it will. But unlike last year, they are winning comfortably in victory