cherdano, on 2016-December-18, 12:15, said:
Guys what are you talking about?
4S as cue?? After West couldn't bid more than 3C first round??
4S is natural no matter what the opponents tell me. At least 6-5 of course.
He can not have 5-6
♠ to start with. That hand would start 4
♣ over 2
♦ 
(or whatever their 2 suited M+m bid over 2
♦ , according to my little search among some decent pairs, I found they play 4m=m+
♥, 3
♠=sp+m
I imagined W could have something like
AQx
Void
Qx
AKxxxxxx
But I have to admit as you said, the alert given more than my logic made me lean to it. 4
♠ being natural is probably the best with 4 card spades and a hand that is willing to play 5
♣ by himself if can not find a decent spade fit. Usually 7-4. After all, if there is something fishy about the alert, pd can easily hold 4-5 card
♠. I do not think any W can afford DBL to show 4 card spades with 7-4 hand to avoid 5
♦.