Piqued my interest regarding fumble stats, so I looked it up. Fumble rate is apparently not conveniently aggregated, but I found this list of NFL RB's with 3000+ career rush attempts and how many fumbles they had:
https://www.statmuse.com/nfl/ask/low...-3000-attempts
If you do the math:
- Curtis Martin was a freak, fumbling once every 121 attempts.
- Ladainian Tomlinson was next best at once every 102 attempts.
- Jerome Bettis once every 85 attempts
- Frank Gore once every 81 attempts.
- Barry Sanders once every 75 attempts.
- Emmitt Smith once every 72 attempts.
- Edgerrin James once every 69 attempts.
- Adrian Peterson once every 66 attempts.
- Walter Payton and Marcus Allen were worst, fumbling once every 45 and 46 attempts respectively.
If you do the math on JT, he's got 13 total fumbles on 1228 carries. Meaning he fumbles once every 94 attempts, which would be good for third on this list. Even if he gets worse in the latter part of his career, he probably ends up in the range of Sanders, Smith, James, and Peterson at worst.
Just to give an idea.