Bridge computations

Doubling

How many tricks do you expect
to set the contract?

In the diagrams the possible win by a (re)double is compared to the possible loss. The win is the extra score which the (re)double gives if the contract is set. The loss is the extra score which the opponents get if the contract makes. The diagrams show bars for odds against the doubler. If the value is 2, you need at least odds 2:1 in favour of setting the contract before a (re)double pays off.

 

Doubling expecting no more than 1 undertrick

 

The opponents are not vulnerable.

1.4 1.8 7.2 7.6 3.0 3.4 3.8
Contract:1234567minor
1.6 7.2 7.8 3.4 4.0 4.6 5.2
Contract:1234567major
1.8 7.4 3.0 3.6 4.2 4.8 5.4
Contract:1234567sans

The opponents are vulnerable.

0.7 0.9 5.6 5.8 1.5 1.7 1.9
Contract:1234567minor
0.8 5.6 5.9 1.7 2.0 2.3 2.6
Contract:1234567major
0.9 5.7 1.5 1.8 2.1 2.4 2.7
Contract:1234567sans
 

Redoubling expecting no more than 1 undertrick

 

The opponents are not vulnerable.

1.1 3.1 3.5 3.9 2.7 3.1 3.5
Contract:1234567minor
2.9 3.5 4.1 3.1 3.7 4.3 4.9
Contract:1234567major
3.1 3.7 2.7 3.3 3.9 4.5 5.1
Contract:1234567sans

The opponents are vulnerable.

0.5 2.2 2.4 2.6 1.3 1.5 1.7
Contract:1234567minor
2.1 2.4 2.7 1.5 1.8 2.1 2.4
Contract:1234567major
2.2 2.5 1.3 1.6 1.9 2.2 2.5
Contract:1234567sans

Sidst rettet 9/10-2017.