Ranges for natural non-forcing bids

Larry Hammick, larry@hammick.com
2000.01.05

Let's suppose that our side wants to be in game with 26 points
or more, wants to stay out of game with 24 points or less, and
is willing to play for a game or for a partial with 25. (We
assume that a suitable denomination is available and that
"points" is suitably defined.) Then any natural non-forcing
(NNF) bid which is one trick below game, needs to have a range
of at most two points, ee.g.
	1NT (15-17)	2NT (8-9)
or
	1S		3S (10-11)
or
	2NT (21-22).
It the range is any wider, it is a mathematical fact that we
will miss some 26-point games or play in some 24-point ones.

Now an NNF bid which is two tricks below game may have a range
of 4 points, ee.g.
	1S		2S (6-9)
or
	1D		1H
	1S		1NT (7-10 HCP)
In such a case, opener bids again if 26 points may be there. If
he does, responder goes on if he is in the upper half of his 4-
point range:
	1S		2S
	3S (17-18)	P (6-7) or 4S (8-9)
but
	1S		2S
	P (13-16) or 4S (19-20)

In each case game is reached with 26 or more and is not reached
with 24 or less.
Continuing the calculation, a bid three tricks from game (1H,
1S, 2C, 2D) has an 8-point spread, e.g. 12-19 HCP for an opening
1H on 3-5-3-2. In
	1H 	2H
	?
opener bids again if he is in the upper half of that range, i.e.
16+ HCP. With 18-19 he bids 4H.

The above theory, if you buy it, has various practical
implications, such as the following.

1. Opening 1-bids are badly overloaded if the system has no
forcing opening which is not game-forcing or nearly so. The
commoner remedies for this problem are the forcing 1C opening
and the Acol 2-bid.

2. A weak two bid, except perhaps in third position, should be
limited to 8-10 HCP, or a poor 11, or a very good 7. (A fair 11
HCP and a 6-card major calls for a 1-bid, I assume.) The 6-12
range announced by many pairs is much too wide, especially if
the distribution is quite variable.

3. A raise or jump-raise of a minor-suit opening may have a
wider range of playing strength than is normally thought. If 3NT
is in view, however, its strength valued at NT is narrower.

4. Some conventional calls, such as Flannery 2H or Precision 2D,
need a spread of at most 4 HCP, or less if the distribution is
somewhat variable.