Safety Plays
How to handle common suitcombinations
Safety plays are a form of insurance against bad breaks.
Suppose for example, that a normal division of the adverse cards would enable
you to lose no tricks at all in the suit that interests you, whereas against
very bad distribution you might lose 2 tricks; if there is a way to lose just
1 trick, whatever the distribution, than a safety play is available and you
must employ it, whenever the contract depends on losing not more than one
trick. Putting it another way, you sacrifice a trick when the distribution
is favourable, but when it is unfavourable you make sure not to lose two tricks.
It is essential to know the standard safety plays. In principle you can figure them out at the table, but if you never saw them, you will not have the time to do.
You must seen a lot of these examples. You can learn the standard patterns by heart. But best is, you do some practice:
Take a deck of cards. Sort out the 13 spades. Take one of the beneath examples e.g. #6. Deal four you and dummy the given cards.
Now try every thinkable line with every possible distribution of cards between the defenders. Write down how many tricks every line loses against each distribution.
For #6 I made this for you with percentages.
You can proof the distributions and calculate exact probabilities with the MissingCardsCalculator.
It seems difficult, but once you have understood the principle, you will enjoy.
ÜBUNG MACHT DEN MEISTER
Practice makes perfect.
Nr. 
Nr, 
Declarer 
dummy 
To lose 
Adverse cards 
Solution 

1. 
10 
A1032 
Q87654 
1 
KJ9 
The only problem is a 3/0 distribution. You must play low against the Q. If LHO shows out you can finesse on the way back. 

2. 
10 
AJ432 
Q9876 
0 
K105 
Play the Q first and finesse the 10 later, if RHO has K10x 

3. 
9 
AJ8xx 
Qxxx 
1 
K109x 
The only distribution to worry about is RHO having K1097. If LHO has these cards there is nothing you can do
about. 

4. 
9 
AK9xx 
Qxxx 
0 
J10xx 
You have to worry only about 4/0 distribution. If LHO has J10xx there is nothing you can do. You must lose 1 trick. But if RHO has J10xx you must play the Q first and finesse twice, if you see, that LHO shows out 

5. 
9 
AK9xx 
Q10xx 
0 
J876 
See the great difference to #4 in view of the 10 additional. 

6. 
9 
AQ109x 
xxxx 
1 
KJ32 
You cannot be sure losing only 1 trick. But you give yourself the
best chance by playing low from table to the A and play accordingly what the
opponents play. Take the A if RHO plays low. 

7. 
9 
AK98 
76543 
1 
QJ102 
If the suit is distributed 2/2 you'll make all tricks, by cashing AK. If it is 3/1, you'll lose 1 trick whatever you do. But If RHO has QJ10x you can hold your loss to 1 trick, if you finesse on the first round. You pay the premium of an overtrick if the suit is distributed 2/2. 

8. 
9 
A109xx 
K876 
1 
QJ32 
If you need all tricks, you should play A or K, hoping for 2/2 distribution
or restricted choice. 

9. 
9 
AQxxx 
xxxx 
1 
KJ109 
Here is the same principle as in #7. Give up a possible overtrick, if RHO has Kx, but you can ensure not to lose 2 tricks, if LHO has K alone by playing the A first. 

10. 
9 
KJ852 
Q643 
1 
A1097 
This is the same motif as in #3. You must protect yourself, if RHO
has A1097. Therefore your first lead must
be the Q. 

11. 
9 
A9xxx 
QJxx 
1 
K1087 
You have a perfect safetyplay against either opponent having K1087:


12. 
9 
A10984 
Q765 
1 
KJ32 
The double finesse loses if LHO has KJ or KJx. The rite percentage
line 

13. 
8 
AJ87x 
K9x 
1 
Q10654 
Play the A first and finesse the 9, if LHO plays low. You'll lose only 1 trick if either opponent has Q10xx. 

14. 
8 
AQ5432 
J6 
1 
K10987 
You'll lose 1 trick if opponents cards are 3/2. You win against either opponent having the stiff K by playing the A first. 

15. 
8 
AQJxx 
xxx 
1 
K10987 
Play the A first and then lead up against QJ (if
necessary twice). 

16. 
8 
A1098 
Q765 
1 
KJ432 
Contrary to # 12 the right line is here the double finesse. 

17. 
8 
A1032 
K654 
1 
QJ987 
"You must worry only about 4/1 distribution. If LHO has 4 cards 

18. 
8 
AK832 
1065 
1 
Q10974 
No problem if the suit is divided 3/2. Play the A first and if either opponent has single Q or J or LHO single 9, you should then play small against the 10, ensuring 4 tricks if LHO holds Q9xx or J9xx or if RHO holds QJxx, Q9xx or J9xx. 

19. 
8 
AK10xx 
xxx 
1 
QJ98x 
You must worry only about 4/2. If LHO has 4 or 5 cards you must lose
2 or 3 tricks whatever you play. 

20. 
8 
AQxx 
xxxx 
2 
KJ1098 
Play the A first and
then from dummy low to the Q. There is 

21. 
8 
AQxxx 
10xx 
2 
KJ987 
"If the suit breaks 3/2 you can't lose more than 2 tricks and
if 

22. 
7 
AKJ5 
432 
1 
Q109876 
Play A and K and then small against the J.


23. 
7 
A10753 
K9 
1 
QJ8642 
If the suit is 3/3 you lose 1 trick anyway. If it is 5/1 or 6/0 you'll
lose more than 1 trick for sure. As often the 4/2 distributions are
of interest. The best line is to finesse the
9 to the first trick. Playing A and K wins only against either opponent having QJ. There is another matter, if you have A10975 – K3. Now playing A and K has the better percentage. 

24. 
7 
QJ32 
K54 
1 
A109876 
No problem if the suit is 3/3. No chance if it is 5/1 or 6/0. 4/2 is the matter again. Play low against QJ and if the Q holds back to dummy and play again low against the J. You'll win whenever the opponent before QJxx has Ax!!! 

Try these link too: http://www3.telus.net/ldh/bridge/safety.txt