Using a Custom Field with two Custom post types

Hi,
I have 2 custom post types (let say “soccer” and “basketball”).
And I have custom field (lets say winner a radio button with 3 values – HOME TEAM, NONE, AWAY TEAM).
I do not understand how can I use this custom field with both custom posts. I can only select a single post type to attach the custom field.
Can somebody help?
Thank you!!!