In the section on takeout doubles we explained that these doubles are asking partner to bid. In the bottom two sections of the panel above you can see more cases where we use takeout doubles to ask partner to bid.  In the middle section, double says ‘I have the other two suits – which do you prefer?’ and in the bottom section the double says ‘I believe you have some points, please bid something unless your holding in the opponents’ suit is soo good that you think they can’t make even this lowly part score’.

In the top section, the takeout double has an extra meaning. Where partner has opened a minor suit, and RHO has bid a major, we use double to show the other major. This is useful because it means we can convey information about our beloved major suits very economically (opponents’ bids in brackets):

• After 1C/1D – (1H), we can distinguish between a responding hand with only four spades (double) and a responding hand with five spades (bid 1S)
• After 1C/1D – (1S), we can show hearts, but saying we can’t bid them at the two level because we either don’t have enough hearts (5) or enough points
• After 1C – (1D), we can show both majors without raising the level of the bidding at all. With just one 4+ major you can bid it at the one level.