Strong Notrump - Historically, the range for a 1 Notrump opening bid
was 16-18 High Card Points in North America. Over the years, many players have
lowered the range to 15 - 17 High Card Points - this approach still captures
the essence of the strong bid that indicates the partnership likely owns the
majority of points.
The lower range also enjoys a greater frequency of
15 = 4.4 percent
16 = 3.3 percent
17 = 2.4 percent
18 = 1.6 percent
likelihood opening 1 Notrump based on strength alone is:
15 - 17 HCP =
16 - 18 HCP = 7.3 percent
Therefore, the lower range occurs 38
percent more frequently
than the legacy stronger 1 Notrump range. Acol bidders playing 12-14
points, K-S bidders playing 11-14 points, and some Precision players who
enjoy 10-12 points enjoy an even greater frequency of opening 1 Notrump.
See Probability of High
Card Point percentage chart.