Complex sentence: He took 99 wickets at an average of 14.39, placing him third in the Yorkshire averages; that year, the county won the official County Championship, which had begun in 1890, for the first time in their history.
Split into simpler sentences: He took 99 wickets at an average of 14.39, placing him third in the Yorkshire averages. That season, Yorkshire won the official County Championship, which began in 1890, for the first time in their history.