System is a fairly natural 2/1 5-card major, partner is inexperienced but promising and a precise bidder.
The natural bid is 1♣, although the possible rebids are not all plain sailing. But opening 2♣ is not going to help here and it's well outside our agreements for 2NT, even if one doesn't need K&R to see it is more like 21 than 17 points. So I guess it has to be 1♣ (2+cards, denies 5-card major). Partner responds 1♠ (4+ cards, does not deny 4-card ♦).
Your rebid here?
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I rank
1. 3N = NAT with good ♣s. Highly descriptive as TramTicket recommends.
2. 2♦ = REV. If you are going to manufacture a reverse, then better a minor than a major
3. 2N = BAL 17+-19. 3N is the most likely game.
4. 3♣ = NAT. But 3N might make opposite a Yarborough. ♠ x x x x x ♥ x x x ♦ x x ♣ x x x