Blocked From the Top

A giver's suit is blocked from the top when it is impossible for giver to run out of the suit just by following suit. She must have a pitch from a different suit if she is to play all of a suit that is blocked from the top. Having an ace in a suit automatically blocks that suit from the top. Having two cards queen or above blocks a suit from the top. So does three cards ten or above, four cards eight or above, five cards six or above, or six cards four or above.

The significance of having a suit blocked from the top is that taker can never get his first pitch while playing that suit.

When the dealer looks at her hand and sees that all four suits are blocked from the top then she knows that it is mathematically impossible to make the hand. Her reasoning goes as follows:

The team cannot get any pitches in this hand. We cannot get the first pitch in any suit since each suit is blocked from the top. Since I cannot run out of any suit without pitches from an outside suit, I will not be able to play all of my cards. So we will not be able to make the hand.