Complex sentence: He struggled in the 1905 season, registering a 19-15 record, and in 1906, registering a 23-17 record while leading the AL in earned runs allowed.
Split into simpler sentences: He struggled in the 1905 season, registering a 19-15 record. In 1906, Chesbro registered a 23-17 record while leading the AL in earned runs allowed.