Fortune favours home?

A reader looks at penalty stats

It is often claimed that referees give more penalties against the away team than the home team, and people then start to theorise as to why this should be. However Planet-Rugby kindly publishes statistics about penalties in the Super14, and so I decided to see if the initial premise was true.

If you like the anecdotal approach, you would probably be satisfied to note that the Cats conceded 89 penalties away and only 54 at home. However I could counter that the Bulls conceded only 50 away and 71 at home.

How about the overall totals? 846 home; 862 away. Case proven? Not a bit if it. Basic statistics will tell you that such a result could easily have been obtained if the penalties were distributed entirely at random. The totals are only 8 away from the average of 854.

Are all teams slightly biased the same way? No. Eight of the 14 teams averaged more penalties at home than away.

Is the total number of penalties per team relevant? 72% of the time, a team gave away from 7 to 12 penalties per game, so there is no great variation anyway, and I could find no correlation between penalty totals and the home/away ratio.

Well it must be something. How about wins and losses? That is a little tricky. Do we take into account the changing mindset as the scores fluctuate throughout a game? However if there is anything in the idea, something ought to show up simply by looking at penalties conceded against the final result.

Average penalties against the winning team: 9.6; against the losing team: 9.3. Statistics for individual teams do not really tell us anything because many teams had only a small number of wins or losses.

There are probably a lot more theories out there, but I prefer to follow the principle of Occam's razor: referees penalise what they see happening in front of them, unaffected by outside factors.

By Peter Shortell

For the last round of Super 14 stats, click here.