Scoring variations

Rounding

In the traditional Mah Jong special paying sticks worth 2, 10, 100 and 500 points are used for making the payments. Normally the total score for the hand is rounded in order to simplify the calculations. Though this is not necessary in Four Winds, the rounding options are retained for the sake of completeness.

Rounding rules, as most of the other rules, vary according to the version of Mah Jong:

Round off/up to nearest ten before doubles/han. In most rules no rounding is done before applying doubles (han). However, in the American Modern rule preset the points are rounded up (e.g., 22 becomes 30) to nearest ten before doubles. In the Japanese Modern rule preset, where a settling table is used for calculating the final score, the basic points (fu) are rounded up to nearest ten before adding doubling factors (han), and the setting cannot be changed. In Hong Kong Mah Jong and other rules where the scoring is based on a faan-laak settling table and where the point unit is not used, the "rounding before doubles" is not meaningful and cannot be used.
Note: You can specify whether the points are rounded off or up to nearest ten by clicking the + button beside the option. Rounding off means that 24 becomes 20 and 25 becomes 30, rounding up means that 21 becomes 30.
Round off/up points to nearest 1/10/100. In most rules the total score is rounded off to nearest ten (e.g., 64 points is rounded off to 60 points, 65 points to 70 points). The rounding is done after all points have been calculated for the hand, but before applying the payment doubles (e.g., East often pays and receives double). However, in modern Japanese Mah Jong the points are rounded up to nearest hundred (101 becomes 200), and only at the time of payment (e.g., 20 fu points with 2 han gives according to the settling table 320 points, which could be doubled to 640 points for East and rounded only after that up to 700 points). In the Australian rules the points are rounded off to nearest hundred at the time of payments (e.g., 149 points becomes 100 points and 150 points becomes 200 points).
Note: You can specify whether the points are rounded to nearest 1, 10 or 100 by choosing the unit from the list box and specify whether the points are rounded off or up by clicking the + button beside the option. Rounding off means that 24 becomes 20 and 25 becomes 30, or that 149 becomes 100 and 150 becomes 200 (if the rounding unit is 100), rounding up means that 21 becomes 30, or that 101 becomes 200 (if the rounding unit is 100).
Note too, that the unit of 1 is meaningful only when used with the Round at paytime option since you cannot have fractions in the total score (the payment, however may well be a non-integer value).
Round at pay time. Used typically in the Japanese Modern and Australian rules. Specifies that rounding is done only at the time of payment, i.e., after calculating all points for the hand and determining the sum each player's must pay to the winner (and to other players, if losers are paid, as well).
E.g., if the winner's points are rounded off to nearest hundred, and winner's (East) score is 360 points, and the East is paid double, each loser pays 720 points, rounded off to 700 points, to the winner. Without using the Round at paytime rule option the winner's points would have been first rounded off to 400 points before applying the payment double, which would have resulted in each loser paying 800 points to the winner. The effect of this rule option is particularly significant if the rules require that the discarder pays for all losers (as in the Japanese Modern Mah Jong). E.g., if the winner's score for his hand is 320 points and he is dealer (receiving and paying double), the score is multiplied by 6 (each loser pays double), and the resulting sum is rounded up to nearest 100, which makes 2,000 points. This sum is paid by the discarder. Without using this rule option the discarder would have to pay 6 times 400 points (320 points rounded up to nearest 100 before counting the doubles).
Round up from 6x, down from 5x. If enabled, specifies that the values below 6x are rounded down to nearest one, ten or hundred and values greater than or equal to 6x are rounded up to nearest one, ten or hundred. E.g., 25 is rounded down to 20 and only 26 up to 30, and 159 is rounded off to 100 and only 160 up to 200. Normally the values are rounded arithmetically (down for values smaller than 5x, up for values greater than or equal to 5x). This option is available only if either of the rounding rules is specified with the "rounding off" option enabled.

You can specify the rounding options on the Extra payments and Rounding page (under the Scoring section in the category tree of the Preferences dialog box).