There are only three quarterbacks in the history of the Los Angeles Rams to throw a “perfect game”, which means posting a maximum passer rating of 158.3.
James “Shack” Harris, who was drafted in the eighth round of the 1969 NFL Draft, was the first to accomplish this feat. His perfect game came against the Rams’ rivals, the San Francisco 49ers, when he completed 12 of 15 passes (80%) for 276 yards and a touchdown. He also added nine carries for 23 yards and another score, though these stats don’t factor into the passer rating.