THE jump cuebid is quite a rare overcall. Most play that it shows a solid suit, and asks partner to bid 3NT with a stopper in opponent’s suit.
(It may simply show a very strong pre-empt, in which case you can remove 3NT to your real suit.) The North hand here is typical – there is no guarantee that 3NT will make, but it will have chances if South has a heart stopper. The hand comes from the Scottish Cup quarter-final, and Alan Mould sat South. What should he bid over 3H? Clearly he is too strong for just 3NT. Partner presumably has a running diamond suit, and if it is a seven-carder South can count ten Sure Tricks. Partner should have a little more than just diamonds, so Alan decided to bash 6D, protecting his king of hearts from the opening lead. This is a fine contract, with 11 top tricks, and a twelfth if a heart is led, or declarer can establish spades. Since there are just 12 missing points declarer will play West for the queen of spades and make twelve tricks with ease. West, Les Steel, made no mistake with the opening lead: ace and another heart sank the contract when East ruffed. Should Alan have opted for 6NT? That would avoid the ruff, but there may not be 12 tricks to cash. If dummy has the doubleton king of spades, so that spades can be ruffed out, 6D is superior - and West may not lead a heart when he knows South has the king.