Probabilities of Seismic Openers
| Bid | Prob (NV/V) | Description |
| Pass | 38.99% / 41.47% | None of the below (other openings assumed to be very improbable) |
1 |
9.759% | 16+ HCP and any shape |
1 |
15.7% / 12.71% | NV - Rule of 18, 2+,
no 5M. Not 10-12 balanced or 10-15 6+
or 5/4M. V - Rule of 18, 4+ ,
no 5M. Not 13-15 balanced or 10-15 6+
or 5/4M. |
1 |
7.327% / 7.853% | Rule of 18, 5+,
 <
. (Balanced opens 1NT when right range) |
| 1 |
7.733% / 8.259% | Rule of 18, 5+,
≥
. (Balanced opens 1NT when right range) |
| 1NT | 12.78% / 12.24% | Balanced hand and 10-12 HCP NV, 12-15 Vul |
| 2 |
3.442% | 10-15 HCP, 6+
or 5/4M, shorter major
< 3. |
| 2 |
0.8403% | 10-15 HCP, no 5-card major, ≤ 5
≤ 1 |
| 2 |
1.05% | 6+, <4,
no 5-card minor, 3-8 HCP, less than a rule of 18 hand. |
| 2 |
1.05% | 6+, <4,
no 5-card minor, 3-8 HCP, less than a rule of 18 hand. |
| 2NT | 0.4501% | 5/5 or better in the minors, 5-10 HCP |
| 3 |
0.2136% | 7+, no 4-card
major or 5. 3-8 HCP |
| 3 |
0.2136% | 7+, no 4-card
major or 5. 3-8 HCP |
| 3 |
0.2244% | 7+, no 4
or 5-card minor. 3-8 HCP |
| 3 |
0.2244% | 7+, no 4
or 5-card minor. 3-8 HCP |