The referee dimension

rugby365.com reader, turned columnist, Anton van der Merwe looks at the referee dimension at the scrums in the latest contribution of his Statistically Speaking series.

A scrum incident entails any of, a reset, scrum ball lost, a penalty, a free kick, a collapse or a wheel. With the advent of the ref's commands to "Crouch .. .Pause … Engage", it now takes three to tango in the rugby scrum.

As was already evident from the first issue of Statistically Speaking not all referees are created equal. This will be evident from this edition of Statistically Speaking.

Scrum Incidents by Ref

rugby365.com readers might recall from last week's column that the stats revealed an approach by Australian teams to the 'dark art' of scrummaging that defied the stats for the other two countries in the Super 14 competition.

To view last week's column CLICK HERE.

Before considering the stats in more detail it is important to reiterate that the ref is of course not the sole determinant of scrum incidents. Nevertheless, a ref that does not assert himself at scrum time is bound to invite all kinds of shenanigans in the scrum. Moreover, a ref who does not fully understand aspects of the art of the rugby scrum will invariably be inconsistent or overreact to certain scrum practices.

Looking at scrum incidents from the perspective of the nationality of the referee vs the nationality of the team putting the ball into the scrum reveals some noteworthy oddities. When considering the graph below along these two dimensions keep in mind that the average scrum incidence per scrum over the fist 10 weeks of the Super 14 competition has been 0.78 incidents per scrum.

There is a lot in this graph, so let's take it step by step.

Australian refs comes in at the lowest incidence level for New Zealand teams (0.51) and South African teams (0.52). For every country's teams their worst scrum incidence occur when a foreign referee is officiating.

For New Zealand teams it is with South African refs, for South African teams it is with New Zealand refs, and for Australian teams it is also with New Zealand referees. From this information one can draw one of two conclusions. On the one hand, it would seem that the dark art of scrummaging is sufficiently varied among the three countries to where referees are unable to apply their particular interpretation consistently when officiating over foreign teams. This would mean much better training with regards to scrummaging is required. On the other hand, referees might simply be biased towards foreign teams.

The exception to the latter statement is of course the stats for Australian referees. Then again, Australian referees might just not be aware of the shenanigans of South African and New Zealand dark artists?

In any case, looking at the graph from the perspective of a team's nationality there are significant variations depending on the ref's nationality. For example, for South African teams scrum incidents vary by 60 percent and for New Zealand teams by 94 percent depending on where the ref is from. The lowest variation occur for Australian teams (20 percent), but this turns out to merely highlight the fact that they are just consistently up to something.

None of the refs, not even the Australian refs, seem able to make sense of what Australian teams are up to in the scrums… In fact, Australian teams with a New Zealand referee officiating average a whopping 1.07 incidents per scrum - that is an average of more than one incident every single scrum!

Not Created Equal

Who are the top three worst referees when it comes to scrum incidents? The referee with the highest overall scrum incidence on his watch is Vinny Munro (New Zealand) with 1.26 incidents per scrum. Next comes Pro Legoete (South Africa) with 1.13 (to be fair he officiated only 1 game) and third from the top sits Jaco Peyper (South Africa) with 1.03. The three lowest on the totem pole are Ian Smith (0.19), followed by Nathan Pearce (0.38) and Stuart Dickinson (0.45). All Australian referees! However, note that Vinny Munro's incidence ratio is 563 percent higher than Ian Smith's!. What in the world is going on here?

Keep An Eye On

Finally, Steve Walsh and the Chiefs in Week Ten did their scrum incidence stats no favours in the Stormers vs Chiefs game. In last week's column we highlighted the game coming up in Week Thirteen between the Waratahs (the worst offenders on their own ball) and the Chiefs (the worst offenders on the opposition ball).

There is of course also the scenario where the top two worst offenders on the opposition ball (the Chiefs and the Cheetahs) will play each other – that awaits us this weekend. Bryce Lawrence (New Zealand) is the referee for that game and he has the following scrum incidence statistics (among the biggest personal variations - 213 percent!) when slicing the data by team nationality.