# Wii Tennis scoring formula?

Has anyone figured out the Wii Tennis scoring formula? IE, how many points you gain/lose based on whether you win/lose, who your opponents are, and how badly you win/lose?

Given enough data points, you could at least come up with a rough estimate, so it seems that someone should've done this, but I haven't found anything online so far.

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It's probably based on Elo. – StrixVaria Nov 25 '12 at 16:04
As nearly as I can tell, Elo only applies to win/lose situations. In Wii Tennis, your score varies based on how badly you won/lost (eg, a deuce win nets you fewer points than a shutout) – barrycarter Nov 25 '12 at 16:52

## 1 Answer

It's rather complicated, I've figured out a good part of it here: http://orden-y-concierto.blogspot.com/2013/04/wii-sports-tennis-skill-points-system.html

Edit: In a nutshell: your score during a game determines a certain amount of skill points to tend to, which ranges from 0 to 1200, according to a table. Your rivals' skill applies an offset to that amount, that can be as high as 1200 when playing against the hardest rivals. If you scored always the same score against the same rivals, your skill points would tend asymptotically towards a certain value. In particular, you can't get 2400 points, because 2400 is the asymptote when winning 40-0 against the hardest possible rivals. If you were able to lose always 0-40 against Sarah/Elisa without changing rivals, your score would tend asymptotically to 1200.

Edit 2: There is a simple way to figure out the base asymptote (before being offset by the rivals' skill). If you lose, it is 10 times the points you got (that is, 0, 150, 300, 400). If you win, it is 1200 minus 10 times the points the rivals got (that is, 1200-0=1200, 1200-150=1050, 1200-300=900, 1200-400=800).

What I haven't been able to figure out yet is how the next rivals' skill is decided as games progress.

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We prefer answers that are a little more than just a link. Can you summarize the contents of the link in your answer? – kotekzot Apr 28 '13 at 16:20
Thank you! This is fantastic. I'm going to compare it to my own results at wordpress.barrycarter.info/index.php/2013/01/23/… and let you know what I find. – barrycarter Apr 28 '13 at 19:27
I'm not sure what you will find. I have reasons to suspect that we don't see the actual rival's skill, only a rounded version. If you always win against them (even if at different scores), the results will be completely consistent because their skill will never be reduced. But it's possible that when you lose, their skill is reduced (although not visibly), botching the predictability. – Pedro Gimeno Apr 28 '13 at 20:55