3-card Spade Support
Guru: Why 4♠ and not 3NT?
MrQ: The moment we left that table my partner said he should have bid 3NT (instead of 4♠) which would mean for me that he’s got enough points for us to be in game (because I already showed 6-9 points) but only 4 spades (and thus a shape of 4333), so just in case I supported him with only 3 spades (not much of a choice after 2♥ overcall) I should pass 3NT or go to 4♠ with 4+ spades. Is this how this should have been bid? Without 2♥ overcall (which by the way seems to be rather risky) I think the bidding would be more straight-forward in this particular case: 1♠ – 1NT – 3NT.
Guru: Yes, exactly. Most people play 5+ card ♠ openings meaning that 4333 hands are opened 1♣ irrespective of system and in ACOL even when you play all natural “four card suits” a 1♠ opening will nearly always be five cards OR only four and 15+ points. So it is usually safe to raise with only three cards. But to save any confusion, the more advanced ACOL players introduced a “prepared” 1♣ which could be 4333 and 15+ HCP.