Ever since learning backgammon, I’ve been fascinated with the theory of early game moves. Many years ago, I started working on a system of notation that would convey early game plays with a single letter/character. Nactation (short for Nack-action-notation) was founded on the principle that characters (letters, symbols) should be
(1) User-friendly.
(2) Efficient.
To satisfy (1) user-friendliness, I wanted the letters to be as associable, and therefore memorable, as possible. Most characters are the first letter of the word that describes its action: Some examples are S, R, P, H, D and U, which stand for Split, Run, Point, Hit, Down and Up, respectively.
Additional letters were created to serve the basic ones. For example, S is the first letter of Split, and splitting plays (which are fully defined as splitting with one number on the die and coming down with the other number) are designated by S as much as possible. The letter Z (which looks like a backwards S) stands for reverse split, was created to serve S, and is not intended to get equal time. It is only when there would otherwise be an ambiguity that it is necessary to resort to Z. (In the case of modern opening plays, this includes only 43 played 24/21 13/9 instead of 24/20 13/10, and perhaps 32 played 24/22 13/10 instead of 24/21 13/11.)
It is easier to remember that S relates to a Split than that Z relates to a Split; it’s that simple. At the outset, I did contemplate many other S/Z schemes, including the one discussed at length in the recent S/Z thread, but I put a premium on user-friendliness (or at least my perception of it).
When I first learned the game of go, my teacher urged me to picture a big go stone with straps around its shoulders, digging its feet into the dirt, leaning forward and strained to its limit to drag an enormous weight, and that each stone I play on the go board should do that kind of work. I feel the same way about Nactation letters pulling their weight, which brings us to their being: (2) efficient.
A common misconception is that Nactations for plays with a given roll consistently translate to a fixed traditional notation. Not so. To accomplish that, it would be necessary to have thousands of characters; even with full integration of lower case, italics, numerals and other keyboard symbols, there would not be nearly enough to go around.
Consider 21S-65R-54. (This is Nactation’s way of saying that Black rolled opening 21 and split with 24/23 13/11, in reply White rolled 65 and ran 24/13, and now Black has 54 to play.) There are two things to notice here. The first is that the concept of “splitting” is not necessarily confined to a play that breaks an anchor. It applies more generally to a play that moves a back checker with one number (and comes down with the other). Otherwise, new letters would have to be added to express variations on the same splitting theme and Nactation would be that much harder to learn.
| gnubg | 156 |
|---|---|
| |
| Stick | 164 |
Position ID: 4HPwAyDgc+QBKA Match ID: cAkWAAAAAAAA | |
The second thing to notice is that with his 54, Black has a choice of two splitting plays: 23/18 13/9, and 24/20 13/8. The first choice moves a back checker with the larger number (5) and is therefore “S.” The second choice moves a back checker with the smaller number (4) and is therefore “Z.” This means that 24/20 13/8 (the smaller split) is necessarily nactated 54Z here, whereas the standard Nactation for 24/20 13/8 played on the very first roll of the game is 54S.
Keep in mind that this is as complicated as it gets, and a scenario as tricky as the one above arises with relative infrequency. When it does, is it confusing? Perhaps for some, until they let go of their notion that nactated plays somehow “should” always translate to the same traditional notations. The system is not designed that way, and if it were it would be profoundly inefficient. Just remember: S splits with the large number (or is the only split); if a choice exists, Z splits with the small number.
(If Z is used when there is only one legal splitting play, there is also no ambiguity – nothing “wrong” in that sense, but I still recommend S in these cases. S = Split is easier to remember and I believe it will better serve those still learning Nactation.)
I am grateful to Stick Rice, who has helped popularize Nactation on a grand scale, to David Rockwell for his patient explanations to people on this forum, and to Tim Chow for organizing Stick’s opening reply rollout data into a semi-nactated chart. (My fully nactated, single-letter version of his chart, freshly updated, can be found at a separate link on Tim's page
Finally, if you would like to understand Nactation (growing in its use on this forum), go here. The explanation is in layers, and Section 1 (only one page) is by far the most useful: reading that will enable you to interpret most of the Nactation you’ll see in bgonline postings. If you get as far as digesting Section 3 (the BEACON letters for doublets), consider yourself an expert!
-Nack Ballard