| Promotion
        is a way of establish- ing tricks.
 | 
        
 | You can develope tricks by promoting your high cards. In the hand diagram at the left, South can not develope tricks in hearts, unless he
      gets rid of East's ace.
 In order to get rid of East's ace South must lead one of his touching
      high cards. If  East plays ace of hearts, South's remaining cards
      will be promoted to highest cards in hearts.Now, you can make two tricks
      in hearts
       |