Micro Bridge - Feature

New Features

What is Micro
Bridge?

Fair Play Algorithms

Bidding Options

Making Your Own
Bidding Systems

Defenders' Signals

Game Mode

Player Mode

Making Hands

Network Play

Other Features

Fair Play Algorithms

The computer is a fair player. The computer player is not as skillful as expert bridge players, but much better than novice players. A computer player bids naturally, plays cleverly, alerts and claims correctly just like an experienced player. Because of this high level of artificial intelligence, you can enjoy playing bridge with other computer players.

Bidding Rule Tables
At the early stage of auction, Micro Bridge decides the bids according to the Bidding Rule Tables (the Data Base of bidding systems). After the bid goes through the Bidding Rule Tables, the computer bids according to a built-in approach. The Bidding Rule Tables characterize the bidding system: five-card majors, weak twos, Jacoby transfers, etc. Micro Bridge offers various kinds of tables that enable you to choose many bidding options.

Monte Carlo Simulation Method
Play algorithms are based on the Monte Carlo Simulation Method. The computer randomly generates unknown hands under known conditions that are derived from information of the auction (HCP range, suit length, number of Aces) and information based on the defenders' signals. For example, 1NT opening hand contains 16-18 HCP and at least two cards in any suit. If the opening lead is a Queen, this must be a singleton, or top of a doubleton, or Queen from QJ.... The computer regards the generated hands just as real hands and decides its bids or plays using double dummy algorithm. The computer iterates hand generation and makes decisions about the bid and play. It evaluates the set of decisions derived from each simulation trial, and then makes the final bid and play.

Double Dummy Play Algorithm
Once all four hands are known, the computer can use the usual artificial intelligence techniques. Minimax search procedure, alpha-beta pruning, situation analyzer, and various programming techniques (progressive trial controlling, buffering, assembler coding, etc.) achieve fast, effective, and deep searches.

Play Level
Micro Bridge offers ten levels of fair play algorithm and the table below shows their categories. In case of the same search depth, a higher level performs more simulation trials than a lower one.


Play  Recommended  Search     Search     Exhaustive
Level CPU Power    Depth      Depth      Search
                   vs Suit    vs NT      (End Play)
. 1     0.1GHz     1 trick    1 trick    Last 6 tricks
  2     0.3GHz     2 tricks   2 tricks   Last 6 tricks
  3     0.5GHz     2 tricks   2 tricks   Last 7 tricks
  4     1.0GHz     3 tricks   3 tricks   Last 7 tricks
  5     1.5GHz     3 tricks   3 tricks   Last 8 tricks
  6     2.0GHz     3 tricks   4 tricks   Last 8 tricks
  7     3.0GHz     3 tricks   4 tricks   Last 8 tricks
  8     4.0GHz   3-4 tricks   4 tricks   Last 8 tricks
  9     5.0GHz   3-4 tricks   4 tricks   Last 8 tricks
  X     6.0GHz   3-4 tricks   4 tricks   Last 8 tricks

Two Types of Tactics
Micro Bridge has two types of tactics. One is for match point scoring game and another is for IMP scoring game. In the match point scoring, computer players avoid bidding borderline games, double the opponents' part-score contracts more often than the IMP scoring when they have the balance of power, and try to take as many tricks as possible (except for slam and doubled contracts). In the IMP scoring, computer players bid borderline games more aggressively, declarer tries safely to make a contract, and defenders try to down the contract even when they give overtricks to declarer.