Restricted choice can be a baffler. check out the comments in the archives of this column, March 7, 2018 and March 15 2010. The Wikipedia article was good, last time I checked. Kind of counterintuitive, but as Kahneman and Tversky thought us, in Thinking Fast and Slow, our intuition often leads us astray with regard to probabilistic reasoning. This is but one example.

Hi Joe1,

Yes and no doubt, The principle of Restricted Choice, when first introduced by Terence Reese many years ago, was a difficult one to just accept by what we had first thought was instead, purely logical mathematical choice

However, after years of encountering its presence, more often than one may expect because of its relative simplicity, you can bet the farm on its accuracy.

Simply explained (if that is possible), it is more likely that the holder (of at least one of the two honors) is more likley to not have a choice of honors played, than to have one, since with a choice he (she) may have played the other one.

The only light I can hope to share is that, through the years, I can verify beyond a doubt (unless I am delusional), the authenticity of that assumption.

Your description about counter intuitive and its complications leading us astray with probabilistic reasoning is an excellent way, if nothing else, to accept it.

Finally, at least my opinion of the small differences in skill between the best players of the world, at least how it now stands, is directly involved with the guessing of the placing of the opponent’s cards (and distributions) in crucial situations since the technical ability of all of them is about the same. allowing the very best practitioners to do the right thing, a bit more often.

IOW the best are better about people psychology, eg, reading their body language.

Good morning Bobby
Could you kindly offer some comment / advice on the relative merits of the various conventions such as Checkback, New Minor Forcing,etc. (after Opener’s 1NT rebid) and also “XYZ” after Opener’s rebid of either 1NT or one of a Major.
I realize a full answer to this broad question might have to be long and complex. Please don’t go to such lengths; just your overall views and some tips would be most appreciated.
Thanks

Hi Clarksburg,

Regarding Checkback Stayman, eg. after a 1NT rebid by the opener after an opening suit bid at the one level, and a response at the one level before the 1NT rebid:

In answer to describing further, old time style sometimes got confusing with individual partnerships then working out what bids were (virtual) sign-offs, (often suit preferences), invitational in that suit, meaning bidding one more than necessary or, of course whatever number of NT (1 and 2).

However either always over the opener’s 1NT rebid, 2 clubs being random Stayman not GF but then checking on both the responder having 5+ cards in his suit or 3+ card support (usually a major) for his partner’s yet non raised response.

Two way Stayman (2C=NFG, and 2D=GF) over the opener’s 1NT rebid is self-explanatory with of course, the only drawback giving up the previous 2C or 2D rebid by the responder as artificial and not natural.

FWIIW I prefer two-wqy Stayman for its simplicity and for its practicality. The big reason why is that after the GF rebid of 2D, then below game raises are forcing and alerts partner to trying to cooperate by providing extra information to him at a lower level than game by inference usually showing either slam interest or less likely, more evidence as to which game (major or 3NT and perhaps even a minor) to seek.

XYZ again features the original responder who if he then bids 2D with his second bid that bid is totally artificial but a GF and while the level is still fairly low, additional information can be exchanged while still being able to stop at game creating consistency in not having to go past a normal game in order to suggest a slam.

In addition (the real reason for this advantage) is that if the original responder then bids an artificial 2 clubs it demands partner to bid 2 diamonds setting forth a limit to no more than game, but possibly only a part score in the mix, when from then on (2D forward) bids are NGF but possible final destinations.

Again a few bids 2C and 2D do not show suits but merely set the table, but neither is that important to show much, therefore I like XYZ, but only for partnerships who take bridge seriously and want to improve their results.

I am certainly no expert on most of this theory, but no one really has to be, but only creates more convenient ways to find right contracts without misunderstandings as to GF or not.

If more is desired, let me know and I’ll find out, but my guess is that you and others can take it from here and run with it (that is if you are so inclined and/or have the time to do so).

Thanks
Having just recently become aware of XYZ, and seeing what it can do, I was quite interested. Hope to be able to try it with one keen Partner.