The benefits of 'DD' analysis
Last week I furnished this hand as a problem - first just the east-west cards, then all four (double-dummy).
| ♠ J4 | ||||
| ♥ KQ42 | ||||
| ♦ AQJ93 | ||||
| ♣ 97 | ||||
| ♠ K76 | ♠ A9852 | |||
| ♥ A | ♥ J73 | |||
| ♦ K5 | ♦ 82 | |||
| ♣ AKQJ1054 | ♣ 832 | |||
| ♠ Q103 | ||||
| ♥ 109865 | ||||
| ♦ 10764 | ||||
| ♣ 6 | ||||
| EW Vul. | West | North | East | South | |||
| Dealer N | 1♦ | Pass | 1♥ | ||||
| 3NT | 4♥ | Pass | Pass | ||||
| 5♣ | End | ||||||
The analysis of the play single-dummy (with just two hands exposed) centred around trying to play the spade suit ensuring south did not gain the lead. There were some other variations where west played diamonds ensuring north won the second round when she was out of black cards. Neither of these plans worked on the layout above, the lie that occurred at the table. After some lengthy inspection of these lines I was just about to give up when I saw that if west runs all his winners ending in the east hand this situation is reached:
| ♠ none | ||||
| ♥ K4 | ||||
| ♦ AQ | ||||
| ♣ none | ||||
| ♠ 76 | ♠ A | |||
| ♥ none | ♥ J7 | |||
| ♦ K5 | ♦ 8 | |||
| ♣ none | ♣ none | |||
| Immaterial | ||||
West will lead to the ace of spades and north must find a discard. If it is a heart then east leads that suit, if a diamond then they are played. Either way north comes to just two tricks and declarer eleven in all. What is the purpose of this exercise? Obviously there is the attraction of informing partner he was down in a cold one (albeit a month later) but also that attempting this sort of analysis is the way to both learn new techniques and avoid fixating on those already known. Note that we have got a much better single-dummy line by analysing double-dummy.
Here the important step is to imagine at trick four what three cards everyone must hold after ten winners have been played. The other consideration is assess whether there will be ambiguity in the endgame. Above there seems to be none; north surely must have four hearts and may be either 1-4-6-2 or 2-4-5-2 but you won't have to decide which, just keep a count on how many hearts she discards (north can't really be void in spades as that gives south five).
Published Saturday 9.Jun.2001