| Occasionally, I find a post with a Nactation that has been superseded, or has an alternate form. Such is the case with the 31P-62S-21 and 31P-63S-21 positions discussed in this thread. |
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| In Nack's preceding post, the "Legend for third roll plays" gives H = Hit (6/3*) as the definition of H (Hit). While that suffices for the many other nacbracs listed in his post, H clearly means 8/7* 13/11 for the two positions above.
In the same legend, L (Lift) is defined as L = Lift (8/7*/5). This definition uses a bit of assumptive Nactation. There are only two L (Lift) plays possible above, to wit, 8/7* 8/6 and 8/7*/5. If one assumes that a reasonable play was made, then L becomes 8/7*/5. Stacking the 6pt, while leaving a direct shot on the bar, is wholely unreasonable. Using non-assumptive Nactation, however, together with the updated Hit/Most/Six Rule, gives a different result. Of the two L (Lift) plays, the one that moves a blot or spare closest to the 6pt will rank highest. In this case, you cannot do better than putting a spare directly on the 6pt, and thus 8/7 8/6 is awarded the capital letter. The alternative, 8/7*/5, moves a spare to the 5pt, and so is assigned to lower case L. |
| Traditional Notation | Hits on These Points (more is better) (higher is better) | Owned Points Not Held by All Members in Family (more is better) (closer to 6pt is better) | Blot and Spare Destinations (closer to 6pt is better) (outer board: farther is better) | Nactation |
|---|---|---|---|---|
| 8/7* 8/6 | 7pt | 6pt* 7pt | L | |
| 8/7*/5 | 7pt | 5pt* | l |
*This is the deciding criterion.
| The nacbracs in the board diagram on the left, are mine. The second entry is l5, that is, lower case L (Lift), down 0.005 points of equity from H (Hit).
The nacbracs on the right appear to be in error. They have been copied verbatim from Nack's post. I am not sure what is meant by H1. A quick 4-ply eval in GnuBg, however, suggests that the intention was to include a lift play using lower case L (rather than the numeral 1). Here are the GnuBg nacbracs: 31P-63S-21 [H l6 X21] /e. Once again, the second entry is lower case L (Lift), this time down 0.006 points of equity from H (Hit). Checking the rollouts at BGO bolsters this idea. Stick has 31P-63S-21 [H l1 X24] /10*5. Perhaps Nack intended H=l (H equals lower case L). [To Nack: has this one been mistyped in your database?] Nack discusses 31P-62S-21 in a post from 2011 where he points out that 8/7*/5 also can be nactated in the O (Outer) and 5 (Five) families. Considering the difficultly in distinguishing lower case L from the numeral 1, it is probably a good idea to use either of these alternatives: 31P-62S-21 [H o5 X34] /15*5 Mike |