Up
Game 10 HCL
9 HCL
8 HCL
stopper
with 5 card M

In this section I am going to dissect the 15-17 NT opening and game opportunities for the partnership.When applying the computer simulation data, please make adjustments according to hand evaluation and opponent bidding.  I am not going to discuss slam opportunities because it is usually fit oriented and control oriented and you must find that out in your bidding system and not just pure HCP, or HCL or HCLS points.

There are also many different style of 15-17 NT opening / response partnership agreements. I am not advocating any specific one. Since I only want to do analysis on one style and I choice the one I use.  No 5 card major. No 7 card suit. No restriction on doubletons. I believe the result of including 5 card major may be different in the % of games made due to higher % of a major game. Other style may not have any significant effect on the %. All data in this section uses about 3.5 million deals and 7 million partnership hands.

First of all let me start with a simple table of probability.

1NT hand condition do not make game make any game make any small slam make any grand slam make NT game
         
15 HCP 52% 38.50% 7.50% 1.93% 33%
15 HCP with no 5 card    52.50% 39% 6.77% 1.61% 34%
15 HCP with 5 card    51.30% 37.50% 8.75% 2.48% 31.20%
15 HCP with 6 card 49.40% 37.14% 10.38% 3.22% 33.05%
         
16 HCP 46.50% 41.44% 9.58% 2.48% 36.04%
16 HCP with no 5 card    46.70% 42.23% 9.02% 2.12% 36.93%
16 HCP with 5 card    46.50% 39.89% 10.53% 3.07% 34.38%
16 HCP with 6 card 44.80% 39.57% 11.58% 4.04% 33.43%
         
17 HCP 40.80% 44.35% 11.37% 3.47% 39.81%
17 HCP with no 5 card    41.20% 45% 10.82% 2.94% 40.85%
17 HCP with 5 card    40.45% 42.83% 12.37% 4.35% 37.59%
17 HCP with 6 card 37.43% 43.68% 13.13% 5.76% 37.92%

There are no surprises here. a long minor suit increases the value of the NT hand.  This is especially true for slam hands.