When the AFL and NFL merged in 1970, all the statistics compiled by the players in the AFL were included in their official statistical history. But when the USFL folded in the mid-1980's, the statistics compiled by the players, including luminaries like Herschel Walker, Reggie White and Jim Kelly were not included in their overall professional football statistics. That is why Bruce Smith is credited with the most sacks in history (200) ahead of Reggie White (198.) If you include the 23.5 sacks Reggie White had while playing in the USFL in 1984 & 1985, Reggie White is the clear #1 all-time sacks leader with 221.5 sacks in his Pro Football career.
In the USFL playing for the New Jersey Generals, Herschel Walker had 7,115 yards from scrimmage.
- 1,143 rushing attempts for 5,562 yards
- 130 receptions for 1,484 yards
- 3 kick returns for 69 yards.
Currently, Herschel Walker ranks 48th in NFL history in total yards from scrimmage, sandwiched between HOF RB Roger Craig at #47, and HOF WR Art Monk at #49. He is 2 spots ahead of soon-to-be HOF TE Jason Witten, who is ranked 50th all-time on the total yards from scrimmage list.
In the NFL, Herschel Walker has a total of 18,168 total yards from scrimmage.
- 1954 rushing attempts for 8,225 yards
- 512 receptions for 4,859 yards
- 215 kick returns for 5,084 yards
If you added his USFL statistics, Herschel Walker would rank #1 on the Total Yards from Scrimmage list with 25,283 yards compiled - 1,743 yards ahead of currently ranked #1 Jerry Rice, and 3,704 yards ahead of currently ranked #2 Emmitt Smith. Even if you exclude his kick return yardage, he would rank 4th all-time, behind Walter Payton with 20,130 Total Yards rushing and receiving.
Walker, even without his USFL statistics currently ranks 45th all time in rushing yards, ahead of HOF players Roger Craig, Larry Czonka, and Terrell Davis. If you add his USFL numbers, he has a total of 13,787 total rushing yards, which would rank him 7th all-time, ahead of HOF RB LaDanian Tomlinson, and just behind HOF RB Curtis Martin. Walker's receiving yards would rank 197th all-time, and his kick return yards would rank 32nd all-time.
In Canton, they call it the Pro Football Hall of Fame, not the NFL Hall of Fame. I'm not sure how they can justify excluding Herschel Walker from among the luminaries inducted into company of legends already included therein.