Over the last couple of days, I came across a few hands which I found some interesting bidding sequences All cases at imps, 1. ♠KQ96 ♥Q ♦Q7543 ♣J64 Favourable vul, it goes 1C on your left, partner doubles, 3C (weak) on your right. Your bid? 2. ♠AT53 ♥K8 ♦KT843 ♣86 All vul, it goes 1C on your left, partner doubles, 1H on your right. Your plan? 3. ♠93 ♥8753 ♦AKT63 ♣JT Vul vs not, once again it goes: 1C on your left, partner doubles, 3C (weak) on your right. Your plan? (a) If you pass, partner doubles again (b) If you bid 3D, partner raises to 4D For all the problems, how will your bidding plans vary if it's matchpoints instead? Thank you in advance!