[samene]

Let's say you are playing in a pickup game. You and P decide to play SAYC. Opps open 1NT. You and Partner have no agreement regarding NT interference so you are going to operate without a conventional option. My SAYC booklet says nothing specific about 1NT overcalls so...

What do you do? Obviously a ton of points would convince you to go with an overcall. So would superb distribution. The question is - how much of each is the minimum to overcall that 1NT opener?

8-16 with 5+ cards?
13+ with 6 cards?
15+ with 4+ cards?
11+ with a weak two-suiter?
10+ with a 5-5?

The standard rules of bidding must apply but they don't seem to specify. Where is this line drawn?

[HeartA]

Jlall, on May 18 2005, 01:08 AM, said:

suit quality, distribution, and vulnerability are the main things. I also would suggest its almost never right to overcall with 5332.

Agree. I really don't like the hcp range.

[Chamaco]

Count losers, not hcp.

For one suiters, you could adapt the requirements from your weak-2 style.
A decent agrement for 2 suiters is the following:

none vuln: 7-losers
KQTxx-x-QJ9x-xxx
QJTxx-x-QJ9xx-xx

favourable vuln: 8 losers
QJTxx-x-QJ9x-xxx
JT9xx-x-QJ9xx-xx

At favourable, Matchpoints, it may payoff to relax the requirements to allow for higher frequency of overcalls (e.g. bidding 44 2-suiters).
At IMPS a little more discipline should payoff.

all vuln : 6.5-6 losers
KQTxx-x-KQJx-xxx
QJTxx-x-KJTxx-xx

unfavorable vuln: 5.5 losers
KQTxx-x-KQJxx-xx
QJTxxx-x-KQTxx-x

[Fluffy]

OVercalling NT or reopening has nothing to do with HCP, you should never overcall on balanced hands, and should always overcall with 5-5 and 6 card suits (unless suits are poor).

[samene]

I appreciate the responses, folks. I've been playing bridge a little over a month and soaking up information is critical right now.

So far, responses eschew a hcp guideline when overcalling 1NT. I can see the logic in this for two reasons:
1) we have a reasonable idea of the opener's shape and loser count.
2) without weakness on opps part, fit is mandatory

As Larry Hammick says on his web site:
I: Length fits with strength.
II: Shortness fits with losers.
In a case where you hold a distributional hand and RHO has opened 1NT, it follows that LHO is likely to have a somewhat distributional hand (i.e. 3 out of 4 players cannot hold 4-3-3-3 if the other is 5-6-0-2). LHO's strength will fit with RHO's strength and you are toast if they choose the trump or end up in notrump. But if LHO has length he must also possess shortness in other suits and, if the trump suit goes against them, their shortness will conflict with their strength and their 'fit' will turn against them. (Bidding theory is, necessarily, very new to me so I hope I am making sense here).
Strength vs. strength usually results in neither side being able to make a contract so disregard strength and look for fit. That is what I am taking away from the posts so far and my own inferences vis-a-vis Hammick's assertions.

On the other hand, I sense a general bias against HCP in general. I realize that HCP count is a crutch. Assessing winners and losers is the objective and HCP count is, in a sense, a dumbing down of that process. Nevertheless, odds are that your RHO is thinking point range when he's bidding 1NT and the chances that he's out-of-shape for the bid are greater than the chances that he's out-of-range for it. Is there a point count devotee with an opinion?

Another (very credible) source has suggested that a solid suit (lots of touching cards) would be a hindrance when trying to make a contract stemming from an overcall of 1NT. Something about entries... I don't understand this. Do you?

Criticism of my conclusions is welcomed...

[P_Marlowe]

Well here is a different view:

If they open a strong NT, forget constructive bidding,
and I mean "forget constructive bidding"
You want to go in safely to disrupt their constructive bidding,
in other words, there may not be a lower limit for HCP, but
there is a upper limit.

In green versus red, any crap will be sufficient to enter, in red
versus green, you should watch your steps more closely, but
even then playing IMP's, most players are very reluctant to
double 2H or 2S.

Of course you need to play a overcall structure, who will give you
a fair chance to find a playable landing spot on the 2 level,
not necessarily your best place, but a place, who gives you a chance
to survive.

An possible convention would be DONT or Lionel.
Usually Lionel is played with 11+ HCP, I would suggest to play it as
11-HCP, i.e. you're partner can only expect 11 HCP, independ from
how many points / defense you actual hold.

You may miss some games, but you will kill their constructive bidding.

With kind regards
Marlowe

PS: If they tell you, this works only against weak oppoenents,
you can ask them, to explain this to Marty Bergen and Larry Cohen.