Dalby was a star linemen at center and defensive end, who led his high school football team, the La Serna Lancers of Whittier, California, to the California Scholastic Federation AAA football championship in 1967.
An all-around athlete in high school, Dalby also played basketball and baseball at La Serna and graduated in 1968.
Dalby was the 100th overall pick of the 1972 NFL draft, selected in the fourth round by the Oakland Raiders.
In his fourth year in 1975, Dalby replaced hall of famer Jim Otto as the starting center, who retired after the previous season.
For the next decade, Dalby was a part of sterling offensive lines which culminated in three Raider Super Bowl victories (XI, XV, XVIII).