Carcass data from more than 38 thousand cattle was used to compare the called and measured yield grade in two different periods: before and after the slaughter plant incorporated another grader in the line to improve grading accuracy. The study shows that the graders accuracy significantly increased. The higher accuracy effected all yield grades, but most notably resulted in more called yield grade 4 and 5 carcasses. This analysis may be a forecast of the impact of instrument grading that will be more accurate than previously called grades.