From what I have seen during OTAs and minicamp, the San Francisco 49ers’ running game is completely different than last season.
First difference: The blocking scheme. Last season, they used a gap-blocking scheme, and the bread-and-butter running plays were “Power” and “Counter.” This year, they seem to be using a zone-blocking scheme, and the bread-and-butter running plays are stretch runs to the outside and read-option plays up the middle.
Second difference: The blockers. Two of the Niners’ strongest and slowest run-blockers the past five seasons, guard Mike Iupati (6'5", 331 lbs) and tackle Anthony Davis (6'5", 323 lbs), are gone.