1. Mantle struck out against Koufax 3 times and hit 1 homer against him.
2. It is far from clear that Koufax was the greatest pitcher ever. (Walter Johnson, for example, who won 417 games and had a career ERA of 2.17, would get some support.) However, Koufax was, seemingly, the best JEWISH pitcher. Though Greenberg rivals him as a player.