February 20, 2015

Research in Rugby growing exponentially-Rugby Research’s Top 15

Paging through the recently published book “The Science of Rugby” edited by Dr Craig Twist and Dr Paul Worsfold (link), which covers everything from strength and power training and match-day strategies for enhancing physical and technical performance, to nutrition and biomechanics in both rugby union and rugby league, I remembered there was a time not too long ago published research articles in rugby were few. To check that I was not falling victim to the recall bias, and because it is a Rugby World Cup year, I did a little Scopus search to determine the current status of research in rugby. Scopus is like Google, but for research papers. Scopus also organises information by year, source, country and affiliation.

So, the 1st search I did was for articles using the term “Rugby” in the title, abstract or part of the keywords. Using the term “Rugby” like this in Scopus means both League and Union papers will be included. Note, I did not exclude areas like humanities and business, and all data points may not represent full research articles. This is what we found…

Number of articles published on “Rugby”

3051 published articles since 1862, 40% of these published in the last 5 years.

Top Journals publishing on “Rugby”

Top journals publishing in rugby are BJSM, JSCS, JSS, and JSMS. SAMJ was the first journal to publish on rugby, BJSM the most consistent, and JSCS the most number of publications in the last 5 years.

Top Authors publishing in “Rugby”

Most published author in rugby- Tim Gabbett (Gabbett Performance)-no surprise there. The head S&C coach of the top performing team in the world, Nicholas Gill, is the 3^rd most published author in rugby research. This says something.

Top affiliations publishing in “Rugby”

Top countries publishing in “Rugby”

We did the same search for “Rugby Union”. Using this search term will only output papers containing “Rugby Union” in the title, abstract or part of the keywords.

Number of articles published on “Rugby Union”

742 articles. Approximately 50% published in the last 5 years.

Top Journals publishing on “Rugby Union”

Top Authors publishing in “Rugby Union”

Top affiliations publishing in “Rugby UnionTop countries publishing in “Rugby Union”

I have a particular interest in the tackle situation. So, I did a search for “Rugby” AND “tackle”. Below are the results…

Number of articles published on “Rugby” AND “tackle”

170 articles. Approximately 46% published in the last 5 years.

Top Journals publishing on “Rugby” AND “tackle”

Top authors publishing on “Rugby” AND “tackle”

Top affiliations publishing on “Rugby” AND “tackle”

Top countries publishing on “Rugby” AND “tackle”

We could do the same searches for any aspect of the sport really (for example, the scrum).

Although research in rugby may be growing at a rapid pace, rugby (league and union combined) is still behind other team sports like football (I did a small search on “football” OR “soccer” and Scopus produced 26941 papers), and there is plenty of scope for research (not too sad about this). There are obvious products from this body of work (better conditioned players, more knowledgeable coaches, reducing the risk of injury, etc), but in terms of conducting research, the exponential increase in rugby research somewhat forces scientists to be creative, and highly applied in their studies.

Sharief Hendricks

February 19, 2015

Superugby R2 predictions: will they fare any better than R1?

Following on from last week, here is an update from Dr Ian Durbach! Thanks again to Ian for putting the article together and for the data from the guys at Superbru…

Dark days for the Rugby Scientists prediction team this past weekend. In case you missed it, here’s how our predictions fared. Games we got correct are in bold but you won’t need to search too hard – there’s only one.

There are always going to be some upsets that predictions get wrong, that’s what makes sport exciting to watch. Results like the Rebels win were totally unexpected. Only 2% of Superbru users got that one right, die-hard Rebels fans we’d suspect. Models get their power by being right on average, so we’re hoping ours will bounce back. The fact that the away teams won 6 of the 7 games is something to watch, particularly as home ground advantage plays a strong role in our predictions.

This week we’re adding two new elements to our model. Firstly, the good folks at Superbru have provided us not just with the overall prediction given by their users, but how those predictions differ between fans of the teams involved, and neutrals. From some of our previous research we know that fans tend to overestimate their team’s prospects by about 5 points. That means we can adjust for that bias, as well as the home ground bias we talked about last week, before making our own predictions.

Here’s what Superbru fans expect to happen this weekend. Take a look at how different the forecasts of the two sets of fans are. Nothing like some good old-fashioned fan bias!

In addition to the new fan predictions, we’ve now got some game results that we can use to take into account a team’s current form. The idea of “form” suggests that teams that win in one week will, on average, tend to keep on winning. Our previous research has suggested that for every 10 points a team wins by in one week, they tend to, on average, win by 2 points the next week. In other words, scoring 10 points this week is “worth” 2 points the next week. Take the upcoming game between the Chiefs and the Brumbies. Both teams won last weekend, the Chiefs by 5, the Brumbies by 44. In making predictions for this week, the Chiefs 5 points are now “worth” 1 point, the Brumbies 44 points are “worth” 9 points. So with just this information we’d predict the Brumbies to beat the Chiefs by 8 points. Of course this is a pretty crude way of making a prediction, but we’ll add it to our existing model and hope it improves our performance!

To recap, our predictions are now made up of three components: predictions made from data on how teams did in previous seasons, which gives an idea of overall team quality; predictions made from recent performances, which tells us about current form, and Superbru predictions, which captures other kinds of information like team selections, injuries, and so on. Our final prediction is an average of these three predictions, let’s hope it does a little better than last week!

What are your thoughts on our predictions? Are we better off tossing a coin or is there some value in the predictive model proposed in this article?

February 16, 2015

Essential rugby seminar for all involved in youth rugby

A great example of science translation in action: don’t miss out on this informative and relevant seminar with a star-studded presentation list. For more information, contact the Players’ Fund (events@playersfund.org.za).