Roush played only 69 games with the Reds in 1916 and finished second in team batting average with .287, behind Hal Chase. 1917 was Roush's first full season with the Reds and by the end of August his batting average of .347 topped Rogers Hornsby who was in second place. An injured leg caused him to miss the final week of the season but Hornsby could not catch his .341 average. At season's end, Roush led the National League in batting average and finished third in hits with 178, only 4 behind leader Heinie Groh.