SAB:   The Support Asking Bid

Below is a description of SAB... This bid is used when responder makes a positive response of 8+ points and the opener rebids a new suit.  Opener's new suit must be a 5+card suit, and the Support Asking Bid is a way to determine how well the responder can help with that suit.

    Step 1     Poor support with fewer than 3 controls
    Step 2     Poor support with 3+ controls
    Step 3     Moderate support with fewer than 3 controls
    Step 4     Moderate support with 3+ controls
    Step 5     Good support with fewer than 3 controls
    Step 6     Good support with 3+ controls
Let's define our terms:
      Poor Support:       0-2 cards
      Moderate Support:       3-4 small cards or a doubleton honor
      Good Support:       4+ small cards or 3+ cards with an honor
Here's an example hand with the auction:
  South      West      North      East   
1      P      1      P     
2      P      3      P     

Opener's 2 rebid asks, "How well can you support my suit, partner?"

The 3 response is the fifth step, which shows good support, but fewer than three controls.