1 | artificial, any distribution, strong – rule of 25 with 14+ points unbalanced or 18+ points balanced |
1 | artificial, either any balanced 15 to 17 points, or a minor two-suiter (5431 or 5422) 11 to 15 points |
1 | natural, four+ hearts, rule of 20 with 10 to 16 points, any other suit may be longer |
1 | natural, four+ spades, rule of 20 with 10 to 16 points, denies four hearts, may have a longer minor |
| 1NT | natural, balanced, 12 to 14 points, no major suit |
| 2 | natural, six+ clubs, rule of 20 with 10 to 15 points, no major suit, may have four diamonds |
| 2 | natural, six+ diamonds, rule of 20 with 10 to 15 points, no major suit, may have four clubs |
| 2 | natural, six+ hearts (maybe five in 3rd), 6 to 10 points (10 to 15 in 4th); less than four spades in 1st or 2nd |
| 2 | natural, six+ spades (maybe five in 3rd), 6 to 10 points (10 to 15 in 4th); less than four hearts in 1st or 2nd |
| 2NT | both minors, at least five-five, 10 to 15 points |
| 3 up | normal pre-empts |
Opening bids from 1 to 2 are considered in detail in neutral openings, and opening bids from 2 up are examined in disturbed auctions. But tempting as opening bids can be, you should look first at the generic Chilli rules, starting with the auction types.