Editing Safety play (section)

===Safety play at IMPs===

{{BridgeHandNWES
|Label =
|Lead =
|K&thinsp;J|Q&thinsp;5|A&thinsp;J&thinsp;7&thinsp;2|Q&thinsp;8&thinsp;7&thinsp;5&thinsp;3
|10&thinsp;9&thinsp;7&thinsp;3|10&thinsp;8&thinsp;6&thinsp;4|9|J&thinsp;9&thinsp;4&thinsp;2
|Q&thinsp;8&thinsp;5&thinsp;4&thinsp;2|9&thinsp;7&thinsp;2|K&thinsp;10&thinsp;8&thinsp;5|10
|A&thinsp;6|A&thinsp;K&thinsp;J&thinsp;3|Q&thinsp;6&thinsp;4&thinsp;3|A&thinsp;K&thinsp;6}} The example deal at left<ref>Kelsey, H.W. Test Your Match Play. Faber, 1977.</ref> is from a team of four game.

South plays 6NT against the lead of the {{Spades}}10. Dummy's {{Spades}}K wins, and the {{Clubs}}A and {{Clubs}}K are played. East discards a small spade on the second club trick.

This particular hand is one of a relatively small group of (non-trivial) deals in which perfect safety is available after the third trick. Single-dummy, using a safety play in diamonds, it is possible to guarantee the contract against any remaining distribution and play of the E-W cards.

South started by expecting to win five clubs, one or two diamonds, four hearts and two spades, but the 4-1 split in clubs complicates matters. Still, a safety play in diamonds will bring in twelve tricks.

It's just coincidence, but the proper diamond play on this hand is the same as the percentage play with this diamond holding, considering the suit in isolation. The best play for three diamond tricks is to play the {{Diams}}A, and then lead toward either the {{Diams}}Q or the {{Diams}}J. This play brings in three diamond tricks 73% of the time.
{{clear}}
Using that play on this deal brings in twelve tricks 100% of the time. Cash the {{Diams}}A, and lead small toward the {{Diams}}Q. Then:

*If diamonds are 3-2, South will always win three clubs, three diamonds, four hearts and two spades.
*If diamonds are 4-1 and West has the singleton, East cannot play the {{Diams}}K on the second lead without setting up both the {{Diams}}Q and the {{Diams}}J. If East plays low and West shows out, concede a club and take four clubs, two diamonds, four hearts and two spades. The same play works if East began with five diamonds.
*If diamonds are 4-1 and East has the singleton, West can capture the {{Diams}}Q with the {{Diams}}K. But in that case West is known to hold four cards in each minor, and on the run of the major suits will be squeezed out of his guard in either diamonds or clubs. In with the {{Diams}}K, West can attack dummy's entry in diamonds or in clubs, but not both. The same play works if West began with five diamonds.

Note that South gives up the 14% chance of four diamond tricks (finessing the {{Diams}}J and then cashing the {{Diams}}A, hoping for the {{Diams}}K onside and doubleton) in exchange for insuring the contract against any diamond break. If South begins the diamonds by finessing the {{Diams}}J, the contract fails against king-fourth in the East hand.