Speaking of “weak jump overcalls”, here was one I made yesterday I’m a little proud of (maybe you’ll find reason to knock me down for it, though?) -
My partnership style is to make sound, constructive opening preempts opposite an unpassed partner - slightly less so if RHO dealt and opened the bidding - but liberty to get creative once partner is a passed hand.
And so, the other day, none vul in third seat, I held:
x
xx
xxx
AJ9xxxx
That’s a hand I would not open 3C in first seat, though many might. Without a better suit or an outside control (A or K), it cannot reasonably play in 3NT opposite a small doubleton - that’s one of the “have respect for an unpassed partner” measures we use. (Make the club suit headed by AQJ or even AJT9 and I would do it, though with the latter, I really ought to have at least an outside Queen.)
In second seat, over a RHO dealer who opened, it’d be different - I would be bid 3C over 1 of a major and hope to get away with it, unless vul against non-vul, just to make their game-going auctions less clear. (Depending on their methods, 1S-(3C)-3S may ambiguity or have double duty as “competing to the 3 level” and “invitational raise of spades”)
But I wasn’t in first or second seat: partner had dealt and passed, and RHO opened not one of a major, but 1D.
Where are all the points? Well, if partner passed as dealer, it seems likely opponents have game values - I have only 5 HCPs.
Where are all the majors? It’s possible partner has some junky 9-10 count with 5-5 majors, but it seems pretty likely the opponents have at least one 8-card major suit fit. And look, they haven’t bid their majors yet! So this is most definitely the time to preempt with my clubs.
So why stop at 3C, which lets them have the 3 level to explore which major suit they fit best in? Let them guess at the game level. I bid 4C. Partner can’t hang me, he’s a passed hand, what’s he going to do other than maybe raise to 5C over 4 of a major?
LHO thought for some time over 4C, and then doubled. RHO then thought for a while, and bid 4S.
After all the long pauses, it was ethically hard for LHO to do much more with his hand, which was a 5431 shaped hand with 13 HCPs: with both majors he could only make a negative double, and for all he knew, partner had a minimum opener with 4 spades, and was simply choosing a game.
Meanwhile, the 1D opener had 4342 shape and an 18 count that had been intending to rebid 2NT. He wasn’t sure if his partner’s double of 4C was based primarily on shape or on HCP, much less being able to picture a 9 card spade fit, so he settled for a “heavy-ish” 4S bid.
It’s an interesting argument about which hand was too conservative in their action, but 4S made six, score it up, next board.
At the other table my hand bid the “normal” 3C, and LHO bid 3S instead of doubling, since it was forcing and he could show his 5 card spade suit while reserving his heart suit to bid at the 4 level (or opener might bid 4H). The hand with the 18 count and 4 spades now drove to slam.