Opportunity-adjusted fantasy points (OFP) strip away player talent and efficiency and focus solely on opportunity.
FORP -- fantasy points over replacement player -- is the difference between a player's actual fantasy point total (FF points) and his OFP (expected total).
Running back adjustments are made as follows:
Rushing attempts: No change
Rushing yardage: Rush attempts multiplied by a rusher's expected yardage based on position, in-box defenders and rush direction
Rushing touchdowns: Rushing OTD
Targets: No change
Receptions: Targets multiplied by a receiver's expected catch rate based on depth of throw, location and position
Receiving yardage: Targets multiplied by a receiver's expected yardage based on depth of throw, location and position
Receiving touchdowns: Receiving OTD
Two-point conversions: OTD multiplied by the league average two-point rate
Fumbles lost: Touches multiplied by the league average rate
Return touchdowns: Excluded due to extreme rareness and randomness
For the complete explanation of OFP and how you can use it to make better fantasy decisions, check out this introduction article.
Here is the 2021 OFP leaderboard for running backs: