First issue: either X or 2c could work out well. Advantages of X: You find your major suit fit, which is necessary to beat the opponents' likely diamond fit Advantages of 2c: If RHO has a hand that has to make a negative double, you are likely in good shape (either partner has diamonds or else partner might be able to raise to 3c, in which case the opponents are apt to wind up in a 4-3 major fit at the three level with half the strength) If RHO bids 2d and it comes back around to you, you'll have an easy X. If you X first and it goes 2d back to you, you'll have to X again, which really doesn't show your hand quite as well. I think X is slightly better in the long run. Note that if your clubs and spades were reversed, you should bid 1s, not X. The same is true if you hold 4513. Bid 1h; don't X (unless your h are just awful). Partner's 1s call: Ought to show a minimum responding hand (5-9 or so). With a horrible hand, partner should pass. 2d rebid after X: Yes, this ought to be more or less a game force. If you have 18-19 and partner has 6 or so, that ought to make game. 2c rebid after X: Yes, this still shows the big hand with a focus on clubs. You aren't strong enough for this, and your clubs aren't good enough. 2c here should also be a game force, because 18 + a minimum responding hand should be enough for game. If you can't find a fit or a d stop, I think you can stop in 4c. How many spades does partner have? He guarantees 4. No, he would not make a "responsive double" with 4. First, if you play responsive doubles in this sequence, that would show spades and clubs. Partner might not have clubs. Second, if you play responsive X here, consider switching. It's too easy for the opponents to make psychic 1h bids if you can't smoke them out with a X that shows hearts. What should you do at this point? You're a bit stuck, I think. If partner has five decent spades and the Jc, you have a game. If partner has Qxxx xx KQxx xxx, you have diddly squat. I think I would compromise between a 2d bid (which is an overbid, given that the Qh is likely useless) and pass, which is a decided underbid, and bid a somewhat strange-looking 2s. Partner's hand is limited to a narrow range, and he'll tend to go forward with 5+ spades but be cautious with only 4 (obviously, the more spades, the more offense). What happened at the table?