| Since the Nackster is not around, let me take a stab at this.
Dmitriy and Stick are both right, but Dmitriy gives the reasoning used under the old rules. It is not an accident that old rules still work (most of the time). The newer rules are designed to support most of what went before. At the same time, they make it more likely that the best backgammon plays are awarded capital letters in a wider variety of situations. Nack explains the newest definitions of D (Down), J (Jump) and I (Inside) in a post from October. Here is what he wrote:
Playing down means moving a checker to or within the outer board. The checker must land in the outer board on the near side, but it can be moved from any point in either outer board. Nack is now relying on the "wrinkle" in Hit/Most/Six to insure that D = 13/11 13/10, and d = 13/8, when 32 is rolled in most early positions. The wrinkle affects blot and spare destinations in the outer board, giving preference to those that are farther from the 6pt. In the home board, and in both far side quadrants, the preference still remains for blot and spare destinations as close to the 6pt as possible. Consider the opening roll 21.
| ||||||||||
| Traditional Notation | Far | Down | Jump | Inside | 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 |
|---|---|---|---|---|---|---|---|---|
| 13/10 | 13/11 11/10 | 10pt* | D | |||||
| 13/11, 8/7 | 13/11 8/7 | 7pt* 11pt | d |
*This is the deciding criterion.
| Note that moving 8/7 is considered to be playing down, so 13/11 8/7 is part of the D (Down) family.
In the outer board, the wrinkle in the 6pt Convention requires checking the blot and spare destinations that are closest to the 6pt, and then giving preference to the one that is farther away. In this example, the blot on the 10pt is compared with the blot on the 7pt. The blot on the 11pt is irrelevant. Similar reasoning applies to the 42P-51S-32 position in Tim's post.
| ||||||||||
| Traditional Notation | Far | Down | Jump | Inside | 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 |
|---|---|---|---|---|---|---|---|---|
| 13/11, 13/10 | 13/11 13/10 | 10pt* 11pt | D | |||||
| 13/8 | 13/11 11/8 | 8pt* | d |
*This is the deciding criterion.
In the third-move position 64R-31P-32 below, the expanded definiton of D (Down), together with the Most-Points Convention of Hit/Most/Six, works to guarantee that the best backgammon play is awarded the capital letter.
| ||||||||||
| Traditional Notation | Far | Down | Jump | Inside | 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 |
|---|---|---|---|---|---|---|---|---|
| 14/11, 13/11 | 14/11 13/11 | 11pt* | D | |||||
| 13/11, 13/10 | 13/11 13/10 | 10pt* 11pt | d | |||||
| 13/8 | 13/11 11/8 | 8pt* | D |
*This is the deciding criterion.
| Once you recognize that moving 14/11 is playing down, the rest of the Nactation is straightforward. Incidentally, the original Nactation Guide states that, "T (sTack or Tower) is distinguished from [L (Lift)] because it only adds to a point already containing three or more checkers prior to the play. L can add to a point that starts with two (or more) checkers." Mike |