Underlying principles of overcalling

Theory and Conventions


M J Bridge



Underlying principles

It should be remembered that in overcalling, perhaps more than in any other aspect of bidding, personal and partnership style and agreement will come into play.  There is an underlying decision to be made about where you are on the spectrum which, roughly speaking, stretches from ‘I will overcall whenever I have thirteen cards in my hand so as to cause the maximum possible disruption to any constructive sequence which my opponents might have planned’ to ‘I will only overcall when I can count at least thirteen solid tricks in my own hand, and even then only at favourable vulnerability.’

I shall assume that your position is not at either of these extreme positions, but it is still true that the styles of a cross-section of good and experienced players would cover a broad band somewhere in the middle ranges.  It is not for me to define a ‘correct’ position on this scale - just to point out the considerations which might make you more likely to overcall on one hand than on another.

In the next few pages (see menu on left) I shall look at some of the factors which might affect your decision to overcall, but first there are a few basic principles which should be firmly grasped:-

on any given hand first convince yourself that the hand fits at least one of the aims of overcalling;

secondly check that your action is consistent with general principles listed below;

and then, if there is any doubt, consider your likely bid(s) in the light of the considerations which follow on the next few pages.

Weak over strong and strong over weak

This is an important principle.

Bid weak hands over strong openings and strong hands over weak openings.

If for example your opponents open with an artificial strong two-bid or a Precision club, then you should compete as high as you can safely afford and as quickly as you can with a weak hand.  If you don’t you can be certain that they will find their way to their best contract which may well be a finely-judged slam.  There is less point in competing immediately if you hold some defensive strength - they aren’t going anywhere anyway, and you have been warned off trying to make a big contract yourself.  If you do have a genuine strong playing hand then one option is to wait for a round - you will get a second chance.

Conversely, if they open with a weak bid - two of a major perhaps - then it is in effect an advance sacrifice. Why make a higher sacrifice yourself on a weak hand and change a plus into a minus?  You must keep all the available bids to show the hands where you need to find the right contract your way.  In this context I mean that you should hold a hand which has sound opening values or better.


My guideline

How strong should I be to overcall a weak opening bid?

At least a good opener.


My guideline

How strong should I be to overcall a strong opening bid?

Less than opening values.

In the case of an opening bid which may be weak or strong, such as the multi two diamond, start by assuming that it is weak and bid accordingly, unless you have specifically made some other agreement.

Sometimes it is not obvious if an opponent’s opening bid should be classified as weak, standard, or strong.

I will propose the following ‘working rules’:-

Treat the bid as strong if it guarantees at least fifteen HCP.

Treat the bid as weak if it guarantees no more than ten HCP.

Treat the bid as weak if it mixes weak and strong meanings.

If the hand doesn’t fall into any of these categories then just treat it as a standard opening bid, either natural or artificial as the case may be.

Artificial or Natural

A second important principle relates to whether your opponents’ bid is natural or artificial.

If their bid is artificial and strong (as in the Precision club) then you should adopt some specific defence.

If the bid does not promise additional strength then you must agree on your method.

Simplest is to treat the bid as natural (double for take-out and a bid in the opponents’ suit as artificial and forcing) in all situations, but more common, and in my opinion superior, is to vary your methods according to whether or not the bid is natural.

If an opponent’s bid is natural then a double will be for take-out;

if their bid is artificial then a bid of their suit will be natural,

and a double will show length and strength in that suit or will have a specific conventional meaning.

As with the previous principle, these are default assumptions which can be overridden by agreement in specific situations.

It is not always quite clear as to what constitutes ‘natural’ and ‘artificial’ in the above.

This applies particularly to opening bids of 1 (and sometimes 1 as in Precision).

Such opening bids should be announced as, for example, ‘could be two’.  If they are not announced then the bid should guarantee at least three cards in the bid suit.

However, it is not uncommon for such bids to be alerted, or announced as (say) ‘phoney’, ‘nebulous’, ‘fishing’, ‘prepared’, or some such description.  In all such cases you should ask what is the minimum possible holding in the suit, and if that number is less than three then you should treat the bid as artificial.  If at least a three-card holding is promised then simplest is to treat it as natural.

Note that there are partnerships out there (but not at a particularly high level) who have never actually agreed exactly what such a bid promises.  Such partnerships tend to hold at least three cards in the suit, and the bid is most easily treated as natural.

Beginner and above

This page last revised 17th June 2017


My guideline

When is a loosely defined one-level bid treated as artificial?

When it does not promise at least three cards in the suit.


My guideline

What happens if they cannot define their bid clearly?

Treat it as natural.

Once you are happy with the aims and principles you should return to the page ‘overcalling’ and follow the links from there for the considerations relating to the opponents’ specific opening bid.