Article comparing NT ranges

[Adam Wildavsky]

http://bridgewinners.com/article/view/campanile-which-notrump-range-is-best/

Sent via Superhuman

[Fred.]

Thanks, Adam.  I find the results fairly unsurprising.  The only 

thing I find myself wondering about is the "abuse".  My own

sense is that I get burned less opening 11 HCP with 2-1/2 or

3 QT than I do opening 12 HCP with 2QT, but this need not

be inconsistent with data based only on HCP.

It would also be nice to see similar data comparting the

performance of non-NT openings depending on the range

of the 1NT not opened.

Fred.

[Fred.]

Steve Wilmer showed me that my second paragraph was unclear.

In KS we open 1m with balanced 15-17 hands and unbalanced

hands.  As Steve pointed out, the IMP expectation for opening

the balanced hand 1m would be minus the expectation for opening

it 1NT playing 15-17 NT.  But, the notrump range also affects the 

bidding on unbalanced hands opened 1m.  The KS treatments of

1m-2m and 1D-2C take into account the possibility that opener

has a balanced 15-17, and won't work very well if opener might

have a balanced 12-14.

By the way, the data shown is average IMP gain per hand.  I'd expect

the measure of the effectiveness of a NT range to be its IMP gain

multiplied by the frequency with which a hand in that range  it is

opened 1NT.

Fred.

[Steve Willner]

On 2/25/22 10:09 AM, Fred. wrote:
> By the way, the data shown is average IMP gain /per hand./  I'd expect

> the measure of the effectiveness of a NT range to be its IMP gain
> multiplied by the frequency with which a hand in that range  it is
> opened 1NT.

That's a good point, too. The other side of it is you have to subtract
the loss when hands in different ranges are not opened 1NT. The lower
the range, the more often 1NT will be opened, and as far as I can tell,
all you have to do to get what Fred want's is multiply each range by the
relevant dealing odds and add or subtract accordingly.

A significant loss for 10-12 will be that you lose _both_ 12-14 and
15-17. That's another way of saying if you open such weak balanced
hands, all your other ranges are necessarily wider, and that has to hurt
at least a little bit.