BRIDGE MASTERCLASS
What would you bid as South? IT WIll take me two days before I get to the recommended answer for this, because you have a lot of possible options. I want first to examine the known data about the bidding thus far and consider how logic and common sense would operate in defensive bidding.
The vulnerability is favourable to your side, yet partner is only able to make a simple overcall after 1♠. (Double or 1nT would have been more significant).
east is good enough to bid freely at the threelevel, which is tantamount to a forcing jump response. It’s already abundantly clear that the opponents not only hold the overwhelming balance of HCPs (at least 25), but also it seems they have a fit in the senior suit (spades) by virtue of your club bidding.
no one has yet bid diamonds, so it’s possible that your partner has a weak long two-suiter, or the opener has diamonds as a second suit and will bid them next. Whichever way you look at it, the opponents have a certain game on, and probably a slam. You have one chance to put an effective spoke in the wheel. Have you decided yet what it is?