Your partner opens one diamond in 1st seat and your right-hand opponent overcalls one heart (both vulnerable). You hold this crummy hand.
Do you pass or bid? This really is a bad hand: two ugly doubletons and only one point. Even so it may be worth competing. You have a diamond fit and six cards in the boss suit. I recommend you make a weak jump shift to two spades. It will hinder opponents’ communication, set the stage for a potential sacrifice, and convey that message to partner. But if you are going to compete with this kind of hand, you must agree with partner beforehand. Discuss it when you are going over your convention card before the game. Here is the relevant section in lower right portion of the convention card:
The box to right of “weak jump shifts: in comp” should be checked. Note that it is in black, so not alertable (weak jump shifts in competition have become standard practice).
When I held this hand it worked out well. We sacrificed in four spades when the opponents could make four hearts.