Oka and uma
Uma is the end game adjusted score. This is most commonly referred as the plus-minus (+/-) score.
Oka
The oka is the point difference between the start score and the target score; and then it is multiplied by the number of players. In general, this can be viewed as the "ante". Typically, the start score and target score are 25,000 pts and 30,000 pts respectively. So, in this case the oka is 5,000 x 4.
Procedure
The end game score is calculated as follows:
- Raw are taken at the end of the game, naturally ordered by the final point values.
- Note the start score and target score point difference, find the oka.
- Subtract the target score from the final point values.
- Add the oka to the winner.
- Divide by 1,000.
- Round to the nearest integer. If the division result produces a digit of 0.5, then the number is rounded down.
- Apply the uma spread, if any.
- If the sum of all four does not equal to zero, then the winner's score is adjusted to produce a zero sum.
Shortcut
This short cut only applies to the distribution of (+20/+10/-10/-20). Using the procedure above, suppose all players unrealistically finish with 25,000 points each. The target points is 30,000 as standard.
| End points | Oka | Minus target | Add oka | Div 1000 | Rounded | +/- | End score | Diff. from start |
|---|---|---|---|---|---|---|---|---|
| 25000 | 20000 | -5000 | 15000 | 15 | 15 | +20 | 35 | +10 |
| 25000 | 0 | -5000 | -5000 | -5 | -5 | +10 | 5 | -20 |
| 25000 | 0 | -5000 | -5000 | -5 | -5 | -10 | -15 | -40 |
| 25000 | 0 | -5000 | -5000 | -5 | -5 | -20 | -25 | -50 |