Note 1: We test and review bridge programs on Windows-based machines. Some of these programs may have Mac versions available.
Note 2: When this article says programs or you can do such-and-such, it means that many or most do it or allow it, not necessarily all. See individual program reviews.
Bridge playing programs allow you to play bridge against the computer. You bid and play the "South" hand and the computer bids and plays the other three hands, with the exception that if "North" takes the bid, you get to play the hand, since your original hand is the dummy.
While there are many bridge programs of varying quality, most of them basically work the same way.
Your hand and a bidding box are displayed. The other (computer) players' bids appear in the bidding box, and you type in or click on your bid (or pass, etc.).
When the bidding ends, you play your cards by clicking on them.
You can usually retract a bid or play if you wish. While this is nice if you clicked on the wrong bid or card, it invites sloppiness in your bidding and play because you know that if your choice doesn't work, you can always retract it.
Some programs have a "tournament" mode in which you are not allowed to retract bids/plays. If you are interested in improving your game, you should force yourself to think before you act, rather than relying on retractions.
In the non-tournament modes, programs will offer hints if you are learning and have no idea what to do next.
You can also bring up boxes which let you review the bidding and play of cards. Programs allow you to look at all the cards in the other hands during bidding and play if you wish.
Another feature programs have is the ability to save deals to disk for later reference. Some programs allow you to load and replay saved deals. This is a good way to challenge friends to play difficult deals you come across.
While some/most programs number the deals so that you can recreate them, this does not imply that there are a limited number of deals. (Well, there may be a limit in theory, but it is probably in the billions for most programs.)
Programs may optionally let you enter parameters to govern the types of deals, such as making sure that your side gets the majority of the points every time when you don't feel like defending.
Programs let you skip a deal if you don't like the hand you got, or if things have gone astray and you want to give up. Again, this cultivates bad habits and it is better to play out every hand.
Bridge programs support some number of bidding conventions. This is an excellent way to learn conventions. You do not have to assign opponents the same conventions that you play.
When a bid is made using one of these conventions, the programs provide some way to alert you, and then you can bring up an explanation with a mouse click.
If you are just learning bridge, you can start with no conventions and add them as you learn them. There are many free places online which discuss conventions, or check out CardShark Bridge Tutor.
One or two programs also let you specify defensive carding and lead agreements.
Programs play each hand individually, as opposed to peeking in the other players' hands (which is called "Double Dummy"). This makes playing the programs more like playing against human competition, since peeking can cause computer opponents to make plays which no human opponent would ever make.
Bridge programs can decide what calls and plays to make by using a combination of two techniques.
The first technique is the use of algorithms set up to handle every possible situation. As a practical matter, the number of possible holdings is so large that not every one of them can be programmed into a computer. This means that the algorithms must be generalized. The quality of a program's play based just on algorithms is dependant upon the quality of the generalizations by the programmer.
The second approach is for the program to generate and analyze as many random card holdings as possible which match the holdings indicated by the bidding and play thus far. The analysis is done by playing out each generated hand double-dummy and comparing the results to pick the best.
The quality of a program's play based just on double-dummy analysis of generated hands is dependant primarily on the number of possible holdings which can be analyzed within a limited time. (The quality of the double-dummy analyzer is also a factor, but high quality is relatively easy to achieve.)
Programs let you adjust their playing strength by changing the amount of time the program has to "think" (examine alternative bids/plays). If you set a program to 60 seconds, that is the maximum time it will take for a call or play. Most of the time, it will only use a fraction of the maximum.
Since a computer can do more thinking on a faster computer in a specific time frame, the playing strength of the program also can vary with the speed of the computer. The same program should come up with better bids and plays on an 800-mhz computer than on a 200-mhz machine since in the same amount of time, it can analyze about four times as many holdings.
However, even at maximum thinking time, the very best bridge programs available play at an intermediate (club player) level, at most.
But the programs are improving all the time. Just in the last few years, bridge playing software has improved substantially, even at the "immediate" playing speeds.
It is highly possible that in the next 5-10 years (some companies are promising sooner), some programs will be able to adapt to any possible bidding system and beat the world's best players. So you had best get your licks in now!