@steve reid,
13 names of Professional football teams:
1. Manchester United
2. New England Patriots (you didn't specify which kind Wink )
3. Arsenal FC
4. Dallas Sidekicks, professional indoor soccer team.
5. Houston Oilers (I also didn't specify a period of time - both, on purpose) #noice!
6. FC Dallas
7. Celtic FC
8. Dallas Cowboys, NFL
9. Seattle Seahawks
10. Houston Astros ((cough cough - wrong sport)) Houston Texans
11. Real Madrid CF
12. Heart of Midlothian FC: that sounds like a football team that plays in JRR Tolkien's Middle Earth realm.
13. San Marino national football team