A quick note on the above.
One of the things we were very interested to see was the extent to which there were stage effects in past RWCs.
This simply means if different factors that we studied played a more or less influential role at different stages during the tournament historically (the tournament structure in this match list chart for RWC 2015 shows the idea. There are four main stages: pools, quarter-final, semi-final, final.)
What did we find ? Well indeed the empirical work showed that there were stage effects. An example: we found that the team’s World Rugby ranking (see latest rankings here) was a good indicator of success at the final stage, i.e. on average the higher ranked team has become champion. This was only so at that stage though, i.e. we could not find that it had an effect (in a statistical sense) at any other stage (e.g. pools, quarter-finals etc etc.).
What’s the insight ? Well imagine if you were trying to plot your team’s path through a tournament. One of the things one could factor in would be that different things are likely to be influential at different stages of the tournament, depending on how far your team progresses.
Observation: there have been stage effects in past RWCs.