When you set your rented GIB robot to play 5-card Majors, the robot plays a basic and natural system, as described below.
You can click on any of the robot bids for an explanation, and pause your mouse over a bid you plan on making to see how your robot partner will understand it.
Please drop us a line at [email protected] if you spot any errors in this document.
Overview
Simplified 5-card major system, with 15-17 NT, weak twos and strong 2♣. Natural, with few conventional agreements.
System Summary
- Over 1-level opening:
- two-over-one response from partner is forcing for one round only
- 1NT response to 1-major opener is 6-9 HCP, no fit, not forcing
- Over partner’s 1NT opener:
- Stayman
- Transfers to majors
- 1NT overcall –> system on
- Defence to 1NT
- X = penalty
- all else, natural
- Doubles
- Negative double through 3♠
- Responsive double
- Michaels
- Unusual NT
- 4th suit forcing
- new minor forcing
- RKCB
Over opponents take-out double
- XX = 10+ HCP
- 2NT = 10+ HCP with fit
- new suits:
- level-1 = forcing
- level-2 = nonforcing
Conventions NOT included in the system
- NO minor transfers
- NO Texas
- NO Gerber
- NO minor stayman
- NO smolen
- NO forcing 1NT
- NO 2/1 game forcing
- NO Splinter (double jumps are weak)
- NO Lebensohl
- NO conventional defence to 1NT (X is penalty, all suit overcalls are natural)
Leads and Carding
- 4th best from a long suit. Note it does not always lead from its long suit.
- Low from 3 small, against both suit and NT contracts
- High from doubleton
- Standard honor leads from sequence (K from AKx, A from AK doubleton).
- Standard carding (high-low shows even number of cards)
When GIB is following to partner’s opening lead, it will usually give an attitude signal:
- High spot card with an Ace or King
- High spot card with a Queen behind dummy’s Ace or King
- Low in any other situation
GIB leads and defends passively, including against no-trump. It almost never underleads an honor, either against suit contract or in no-trump. It doesn’t always lead its longest suit, including against no-trump. Do not assume GIB wants you to return its suit and do not expect it to return yours; it plays as neutral as possible to avoid gifting tricks to the declarer.
Advanced GIB simulates hands based on the auction, to determine the average result of each defensive play, and chooses the one with the best average. Note that sometimes this simulation comes up with the same choice that a human would make, but not always.