In which partner makes a thoughtful bid ...

The most annoying mishaps are those where partner makes a thoughtful bid and I fail to take advantage of the information proffered.  After the disastrous board, when I go back and look at all four hands, I realize that all the clues were there thanks to partner's excellent bid.  Too bad I was clueless at the table where it counted.

Take this hand I played online in a matchpoints tournament. I picked up, vulnerable against not with partner (East) the dealer:

Partner opens 1S and South overcalls 2C.  What's your bid?  In competition, we play pretty much Robson-Segal's system (Partnership Bidding at Bridge). These are your choices:

1. 2S is a minimum raise
2. 3C is a limit-raise or better
3. 3S is preemptive with 4 spades.

Not on the table are 2NT (which would be natural, non-forcing, showing stoppers in clubs and denying support in spades) or any diamond or heart bid which would be negative free bids (at the 2-level) or fit jumps (at the 3-level).

It's a close call between 2S and 3C. I do have a 4th trump, but the quacks are not pulling their weight.  So, I go the low road, and bid 2S.  It gets passed to South who competes with 3D.  Now, do you bid 3S, to show the 4th spade? I decided to pass, reasoning that the 3D bid has just made my hand worse (agree?).  If South has 5 clubs and 4 diamonds, then partner probably is 5-3-3-2.

 But partner now makes a thoughtful 3H bid.  What's that about?  What's his hand?

Obviously, he has 4 hearts, but is 3H a game-try? Of course, not. He passed the previous turn.  He wants to be on the 3-level, so he has no defense against 3D, but wants to suggest where his points lie.  So, what's his hand?  He must be 5-4-1-3 to wish to compete (5-4-2-2 and he'd probably pass).  The bid is more about what to do if the opponents compete to the next level.

I bid 3S, of course and now, North bids 4D.  Back to me.  What's my bid now?

At the table, I failed to take the inference offered by partner's heart bid.  The opponents have a 10-card fit in diamonds.  They are going to be cross-ruffing clubs and hearts. I need to pass, but instead, I doubled to "protect our equity".  Disaster ensued, of course.

This was the complete deal.