opponents could score in 2. West's double denotes shortness in spades and support for the other, unbid suits with a hand such as . Reopening doubles once showed extra values as well. With adoption of the negative double, however (a takeout double by responder), responder must pass with length and strength in the opposing suit. In order to protect against such situations, opener is obliged to double even with thin values, whenever his distribution is suitable. Some pairs even require opener to act somehow; responder's pass is forcing. Equal level conversion doubles This convention (also referred to as ELCD) can change the meaning of doubler bidding a new suit in some situations, for example: This does not promise the extra values in diamonds but shows a hand with 5 diamonds and 4 spades and the values for a normal takeout double. In this case doubler would need to jump in diamonds to show the stronger hand. Some partnerships only play the convention in a sequence like this converting clubs to diamonds. The name is derived from the fact that doubler is converting partner's bid at the same level. This sequence does show a strong diamond hand as doubler has converted at a higher level. Some partnerships also play this convention when holding 5–4 in the majors but with a hand that is neither weak nor strong and, therefore, they cannot use a 2 suited bid (e.g. Michael's cue bid). See also Negative double Negative free bid Support double References Contract bridge bidding Bridge conventions