EW do not come any further than 1NT, whereas 3NT is an excellent contract.
|N/EW|| || |
|♠||K Q 5 4||♠||A J 2|
|♥||8 4 3||♥||K Q 6|
|♦||10 9||♦||A J 8 3|
|♣||Q 10 6 4||♣||K J 8|
|pass||pass|| || |
'I thought you showed 12-14 points', says west.
'Would I double then without shortness in diamonds?' east replies.
'You could have ♦Ax or ♦Kx or ♦AQ', says west.
Who made the mistake?
West made the mistake.
True, east could have doubled on 12-14 points and something like ♦Ax or ♦Kx or ♦AQ. But with such a hand he would have passed west's 1♠ bid!
Doubling first and bidding no trump in the second round, like east does, shows 18-19 HCP. A hand too strong therefore for a direct 1NT overcall. The idea behind it is completely logical: west can bid 1♠ on zero points, a 1NT rebid by east on a mere 12-14 would therefore be suicidal.
This principle applies in many bidding situations: if a player is too strong for a direct bid, he doubles first and does the bid in question in the next round.
| -|| 1♣|| double||pass|
| 1♥|| pass|| 2♠||pass|
| ...|| || || |
East shows a hand too strong for a direct 2♠ overcall. On the assumption 1♣ - 2♠ would promise 12-16 points (intermediate jump overcall), east's actual sequence ('via the double') shows 17+ points.