Which suit to respond to a 1♣ opener (with six or more points but no club fit)

Here are the guidelines:

1. Always bid your longest suit
2. Always respond the cheaper of four-card suits. That way, no fit will be missed.
3. Always respond the higher-ranking of two five-card suits. Start high, so you can finish low.

You may ask why I’ve specified that partner opened 1♣ (rather than, say 1♥ or 1♠). The principles are the same, however, there’s a potential complication which never arises when partner opens 1♣ (as long as your right-hand opponent passes): namely that you may have to decide whether or not you are strong enough to respond at the Two-level. We’ll leave that thorny issue for another time.

Respond to 1♣ with these?.
 

• With (a), respond 1♦. This leaves plenty of room for partner to make her rebid – which could be 1♠. If partner doesn’t bid 1♠, you won’t need to bid your spades for there will be no fit.
• With (b), respond 1♠ “high fives”. Plan to bid 2♥ next time.
• With (c), respond 1♥ – your longest suit. It may be tempting to bid 1♠ but it’s wrong. 

After all, the suit you most want to be trumps is hearts. Those top spades will win tricks whatever the trump suit; the hearts will win tricks only if they’re trumps.