Jay Z owns the nightclub 40/40 in New York, which takes its name from the baseball term.

This image appears in the gallery:
44 Awesome JAY-Z Facts That Will Blow Your Mind

1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 

10. 44 images

See the full gallery: 44 Awesome JAY-Z Facts That Will Blow Your Mind