Another late-night BBO session playing at an IMP table with a friend against random opponents (about nine months ago now, as this sat in my drafts folder for a while). I held at favorable vulnerability: J5 Q75 QJ8765 Q6. After my LHO opened 1C and partner overcalled 1H, my RHO passed. I had a problem, or at least I thought I did. Probably a bid of 2H would be fine. But it seemed odd that nobody had found the spade suit yet and I decided to make life a little harder for them with a jump to 3H. After all, I did have kind of a preempt hand, in a red suit. Different red suit admittedly, but still. At this point, we'd be down 2 against 110 if the opponents played 2S. A push.
Opener passed, presumably hoping we'd get to 4H which he could happily double. Now, partner made an interesting bid showing her real substance, just in case the opponents should end up in spades with me on lead. Only four cards, and the suit opened at her right, but still, a great call, based on the assumption that I had four decent hearts and nothing else.
Perhaps now was the time to bid diamonds. It's actually our best spot (we can make 9 tricks). But we had one good fit, a second fit of some sort (clubs). No need to go muddying the waters with 4D. After my 4H, East sprang the trap. We were headed for a loss of 6 IMPs. But good old West came to our rescue with 4S. Maybe he's a follower of George Rosenkranz who advises that the only time it's allowable to pull a penalty double is when you have an unbid six-card suit. I don't think George advocates always doing it but maybe with a singleton trump and three cards in partner's first suit, it's acceptable.
Unfortunately for West, the one bidding like a crazy person was me, not his partner. I should really have doubled myself but I couldn't bring myself to do it! Coward. Partner doubled and this is where it gets interesting. The point about the PSDB is that when partner bids two suits, they most likely want you to lead the second suit. I obliged with a club lead. Note that a heart suit lead would result in the contract making with two overtricks and total vindication of West! 24 or 25 IMPs were awaiting my lead! Fortunately, we ended in the plus column.
There's really nothing to the rest of the play. We cashed three clubs, one diamond and then I got my trump promotion (is this technically a promotion?)
The moral of the story, apart from noting that I can be a crazy bidder at times, is that when your partner sticks their neck on the block, just asking for it to be cut off, they really want you to lead that suit, not the suit they mentioned earlier. It would be insane to bid 4C without some seriously good cards in that suit after all.