Well first of all the study that shows that South African refs penalise South African teams less is only half correct because the South African teams actually have a similar penalty win ratio away from home as well
I thought I would also do the Penalty count win loss ratio for the away games to get a true reflection on the weather it is indeed bias or if it is actually just a country getting less penalties than the other and the stats show a different story to the article that is going around.
South African Teams actually have a better penalty count win away from home with a non South African Ref as they do at home.
For the Stats I have only used games between SA, OZ and NZ only from the start of 2017 until the end of 2019
I used https://super.rugby/superrugby/ for all the stats and I have included a link to the tables for you to see
I also included all games at home but I used all refs as I thought with Australia only having 2 ref compared to 5 of NZ and SA it wasn’t a true reflection.
I thought I might throw in the yellow card totals for a look as well and as suspected NZ give away more penalties to yellow cards than OZ and SA.
Author: Zane Hendry
More Info link: http://www.greenandgoldrugby.com/community/threads/hometown-refs.18813/page-5#post-1122271