context: McCallister was Tris Speaker's primary assistant during his years as player-manager (1919–1926).
source: McCallister became manager after Speaker's sudden resignation in late 1926.
reference_original: McCallister prese il posto di Speaker dopo le improvvise dimissioni di quest'ultimo alla fine del 1926.
reference_flipped: McCallister prese il posto di Speaker dopo le improvvise dimissioni di quest'ultima alla fine del 1926.