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Analogy for S/Z

Posted By: Nack Ballard
Date: Monday, 23 January 2012, at 8:44 p.m.

In Response To: Nactation notes — S as a substitute for Z (Nack Ballard)

Below is an analogy to the S/Z situation:

51S-21U-44A-33

Blue has 33 to play. He should enter with the 3 and move three checkers either to the 5pt or the 10pt. The plays are very close in value.

If Blue makes the 5pt heavy (as shown in the left-hand position below), it can be nactated with C (the family that covers 3:1 and 1:3 ratios of fars plus jumps). This choice is, perhaps, easiest for the nactator because he need not notice that there is no legal 2:2 play available. But if he does notice, he can (by convenience clause) use C. This can be perceived as friendlier for the reader, who doesn't have to encounter an underlined letter. (It is analogous to the situation where in the opening position the reader doesn't have to encounter 51Z if instead he is given 51S and can think "ah yes, S means Split.")

Likewise, if Blue makes the 10pt heavy (as shown in the right-hand position below), the experienced nactator can, if he likes, use Z without further thought. However, if he notices that there is no 2:2 play (or is himself uncertain about doublet Z), he can target a wider readership by using B. That is, more people are familiar with B than with the doublet usage of Z (1:3 ratio of far + downs).

Blue played C

Blue played B

As you probably know, you may also use J (Jump) for the left-hand play and D (Down) for the right-hand play. Because one is utilizing the ignore-the-entering-portion clause, the analogy to non-doublet S vs Z is not quite as strong as it is with the C and B choices, but the idea is similar. That said, D is the best known letter of all and is likely the letter I would choose to describe the left-hand play to a wide readership.

Nack

Messages In This Thread

• 21$-64K-32U-51D-51Z-65R-53P-44 — Double-anchor position?
  Taper_Mike -- Friday, 20 January 2012, at 6:24 p.m.
  • 21$-64K-32U-51D-51Z-65R-53P-44 — Double-anchor position?
    Stick -- Friday, 20 January 2012, at 8:54 p.m.
    • 21$-64K-32U-51D-51Z-65R-53P-44 — Double-anchor position?
      Daniel Murphy -- Friday, 20 January 2012, at 9:33 p.m.
    • 21$-64K-32U-51D-51Z-65R-53P-44 — Double-anchor position?
      neilkaz -- Saturday, 21 January 2012, at 1:29 a.m.
  • Variant
    Petter Bengtsson -- Friday, 20 January 2012, at 11:15 p.m.
    • Variant
      Taper_Mike -- Saturday, 21 January 2012, at 12:34 a.m.
    • Variant
      Daniel Murphy -- Saturday, 21 January 2012, at 1:02 a.m.
    • Another variant
      Nack Ballard -- Saturday, 21 January 2012, at 3:36 a.m.
      • Another variant
        Daniel Murphy -- Saturday, 21 January 2012, at 4:40 a.m.
      • Another variant
        Taper_Mike -- Sunday, 22 January 2012, at 9:43 a.m.
      • Another variant (23pt): Rollout
        Nack Ballard -- Sunday, 22 January 2012, at 9:15 p.m.
        • Another variant (23pt) — Another Rollout
          Taper_Mike -- Monday, 23 January 2012, at 8:14 a.m.
  • 21$-64K-32-51D-51S-65R-53P-44 & Variant — Rollouts
    Taper_Mike -- Sunday, 22 January 2012, at 10:25 a.m.
    • Nactation notes
      Nack Ballard -- Sunday, 22 January 2012, at 9:01 p.m.
      • Nactation notes — S as a substitute for Z
        Taper_Mike -- Sunday, 22 January 2012, at 10:50 p.m.
        • Nactation notes — S as a substitute for Z
          Nack Ballard -- Monday, 23 January 2012, at 4:29 a.m.
          • Nactation notes — S as a substitute for Z
            Taper_Mike -- Monday, 23 January 2012, at 5:07 a.m.
            • Nactation notes — S as a substitute for Z
              Taper_Mike -- Monday, 23 January 2012, at 7:33 a.m.
              • Nactation notes — S as a substitute for Z
                Nack Ballard -- Monday, 23 January 2012, at 11:54 a.m.
                • Analogy for S/Z
                  Nack Ballard -- Monday, 23 January 2012, at 8:44 p.m.