Home ground advantage
Of course, playing at home helps. You get more support than the visitors and you know the ground much better than they do. You also, it seems, get the bigger share of the penalties.
Below is a summary of penalties per match, those that helped the home team first.
Week One
Blues vs Crusaders (Chris Pollock): 13 + 9 = 22
Brumbies vs Force (Bryce Lawrence): 7 + 10 = 17
Bulls vs Sharks (Jonathan Kaplan): 12+ 11 = 23
Chiefs vs Highlanders (Jonathon White): 13 + 10 = 23
Waratahs vs Reds (Jaco Peyper): 8 + 11 = 19
Stormers vs Hurricanes (Marius Jonker): 18 + 9 = 27
Lions vs Cheetahs (Mark Lawrence): 17 + 10 = 27
Week Two
Chiefs vs Blues (Keith Brown): 12 + 14 = 26
Rebels vs Waratahs (Bryce Lawrence): 13 + 9 = 22
Lions vs Hurricanes (Steve Walsh): 8 + 7 = 15
Highlanders vs Crusaders (Jaco Peyper): 6 + 10 = 16
Reds vs Force (Ian Smith): 11 + 10 = 21
Cheetahs vs Bulls (Craig Joubert): 16 + 6 = 22
Stormers vs Sharks (Mark Lawrence): 15 + 6 = 21
Week Three
Crusaders vs Chiefs (Garrett Williamson): 11 + 11 = 22
Force vs Hurricanes (Jaco Peyper):16 + 6 = 22
Brumbies vs Cheetahs (Keith Brown): 11 + 8 = 19
Highlanders vs Waratahs (Bryce Lawrence): 13 + 9 = 22
Reds vs Rebels (Angus Gardner): 11 + 10 = 21
Sharks vs Lions (Mark Lawrence): 10 + 13 = 23
Bulls vs Blues (Steve Walsh): 18 + 13 = 31
Of the 21 matches, the home team had more penalties on 15 occasions (71%), the away team five times (24%) and on one occasion the penalty count was equal, though the actual figures are not as great as that suggests - 253 to 212.
Of the 465 penalties in the 21 matches, an average of 22 per match, 255 were at the tackle or 54%.
Interestingly the match with most penalties Bulls vs Blues and the match with fewest penalties Lions vs Hurricanes were both refereed by the same referee - Steve Walsh.