Complex sentence: Between 1907 and 1911 they played in three World Series without a win, whilst from 1934 to 1950 they had only two losing seasons and won two of their four World Series.
Split into simpler sentences: Between 1907 and 1911 they played in three World Series without a win. From 1934 to 1950 they had only two losing seasons and won two of their four World Series.