So why did the All Blacks triumph in the Rugby World Cup?

Dr Bill Gerrard, Former Tactical Data Analyst at Saracens and Professor of Business and Sports Analytics, Leeds University Business School 

With the dust now settling despite the early exit of the host nation, the Rugby World Cup 2015 has been widely acclaimed as an exciting tournament that enthralled fans around the world, producing an array of memorable moments; none more so than Japan’s thrilling last-gasp win over South Africa. It was a tournament in which the Southern Hemisphere exerted its dominance by taking all four semi-final places and the Webb Ellis Trophy was ultimately lifted by New Zealand to claims that this All Blacks team is arguably the best ever.

So what did we learn from the 2015 Rugby World Cup – specifically from the All Blacks – about what makes for effective, tournament-winning rugby?

Statistically the main lesson of the 2015 Rugby World Cup was the triumph of what we could call ‘pragmatic’ rugby. Winning required an all-round game with excellence in all aspects of play and the All Blacks were the strongest all-round team in the tournament and, crucially, produced excellence when required under pressure as we saw in the arm-wrestle with South Africa in the semi-finals and then responding in style to the second half comeback by Australia in the final.

When it comes to analysing rugby union, team performance can be broken down into six aspects: set piece, exit play (i.e. own-half possession), the kicking game, defence, attack and discipline. There has been, and always will be, differences in opinion over the most effective tactics. As I have discussed in a previous guest blog, rugby has its own version of the artist-versus-artisan debate in discussing the relative merits of the kicking game and the running game and there is some evidence to support the efficacy of the kicking game in the Aviva Premiership in recent seasons.

What is notable about the 2015 Rugby World Cup is that no single style of play predominated as a winning tactic. Defence did not predominate over attack; kicking did not predominate over running the ball. The more successful teams, particularly the All Blacks, excelled across all six aspects of the game.

Table 1 (see below) displays the results of analysing all 48 games in the tournament and comparing winning and losing performances. Using a t-test with a 10% significance level as indicative of strong evidence of a systematic (i.e. non-random) difference in performance, 20 key performance indicators (KPIs) can be identified with 18 of these KPIs showing a significant difference between winning and losing performances (colour coded yellow). These KPIs span all six aspects of the game. Winning teams were strong in the set piece, conceded fewer turnovers in their own half, kicked more, defended effectively missing few tackles, passed and carried the ball more, making more clean breaks, rucked and mauled successfully, and conceded fewer penalties especially in their own half.

Importantly, pragmatic rugby is not about kicking more, and passing and carrying less. Winning teams averaged 27.8 kicks from hand per game compared to a game average of only 24.7 kicks from hand by losing teams. And winning teams gained more metres from kicking, averaging 445.7 metres gained from kicking compared to losing teams who averaged only 402.4 metres gained from kicking. But winning teams also passed more than losing teams, averaging 153.4 passes per game compared to an average of only 127.7 passes by losing teams. And winning teams made more carries beyond the gainline and carried for more metres. Winning teams gained 488.3 metres per game from carrying compared to only 342.1 metres gained by losing teams.

Table 1 also includes the game averages for the 20 KPIs for the All Blacks and their ranking relative to all other teams with first representing best-in-class (e.g. highest points scored, least points conceded, and so on). A top-five ranking is colour-coded green while a middle ranking (6^th – 15^th) is colour coded amber and a bottom-five ranking is colour coded red.

Table 1: Key Performance Indicators, Rugby World Cup 2015

The All Blacks were best in class for points scored, clean breaks, points conceded and tackle success. Although their ball-in-hand game ranked very highly, the All Blacks also used the kicking game with an average of 27.6 kicks from hand per game, the 6^th highest across all teams.

The full overall rankings for all teams are reported in Table 2 (see below). The total score is defined as the sum of the ranks for all 20 KPIs. These total scores are then ranked with the team having the lowest total score ranked best overall.

Table 2: Overall Teams Rankings, Rugby World Cup 2015

When all teams and all games are included, the All Blacks rank only third overall behind Ireland and South Africa. Surprisingly England, despite their early exit, rank fourth overall ahead of both Wales and Australia. But, of course, the problem with rankings based on all games is that they include the games against the weaker teams which can skew the results massively. A more informative comparison is provided by only including the games between the ‘top 12’ teams defined as those teams finishing third or better in the group stages.

When the rankings are based only on these 20 games the All Blacks emerge as the strongest team with South Africa as their closest rivals. The only Northern Hemisphere team to figure in the top four is Ireland, reinforcing the disappointment of all Irish rugby fans that this should have been the year they finally got the monkey off their back of never winning a knock-out game in the Rugby World Cup.

Based on their performances against Wales and Australia, England rank 10^th out of 12 with only Italy and Georgia below them. Perhaps fittingly the last word goes to the team who won many admirers with their entertaining, never-say-die style of play and will host the 2019 Rugby World Cup, Japan, who on the basis of their performances against South Africa and Scotland ranked 6^th out of 12. On the basis of the 2015 Rugby World Cup, the Land of the Rising Sun is a rising power in the world of rugby.