The great John McGraw allegedly said that Oscar Charleston was the best player he had ever seen. To my knowledge, no one has ever produced a good source for that quote, but if McGraw did believe that, he may have come to that conclusion in the winter of 1924.
McGraw and his wife Blanche were regularly spending a few weeks in Cuba every winter by that point. One assumes they took in some ballgames, at least whenever Mac got tired of the racetrack. In the winter of 1923-24, Charleston was playing center field for the Santa Clara Leopardos, now commonly considered the best team in Cuban baseball history. McGraw would have been aware of how that team was demolishing the competition.
Anyway, it seems that the two men may have had occasion to discuss baseball together. A couple days ago I was looking more closely at this passenger list of the SS Cuba, which arrived in Key West on March 1, 1924 (apologies if you have to zoom in to read the names). Oscar and Jane Charleston are in rows 19 and 20. Who is listed in rows 29 and 30? None other than John J. and Blanche McGraw. I wonder if the two couples spoke during the passage? Indeed, could they have, or was seating on these ships segregated?