Complex sentence: On January 3,1949, at age three, he broke his maiden at Tropical Park and then won two more races, but Jones still thought of him as a lesser contender for Calumet in the' 49 Derby.
Split into simpler sentences: On January 3,1949 he broke his maiden at Tropical Park. Winning two more races, Jones still thought of him as a lesser contender for Calumet's chances in the' 49 Derby.