The scrambling 2NT bid is used after partner makes a takeout double at the two level, and you hold two four
(1S)-p-(2S)-x; p- ??? and you hold:
S: Kxx/ H: Qxxx/ D: Jxxx/ C: xx.
If you bid hearts, you could wind up in a 4-3 fit (and the same with bidding diamonds).
Why guess? If you bid 2NT as a scramble, partner can bid his four card suits up the line.
With S: xx/ H: Kxxx/ D: AKx/ C: QJxx , partner bids 3C over which you bid 3D to deny holding four clubs and then partner bids 3H to
show that suit.
Why play this convention?