Statistical prediction of the 2016 Super Rugby season #superrugby

Yesterday we took a look at the new structure for Super Rugby in 2016 and noted the fixture imbalances it throws up. We also looked at the 2015 format and noted that there are already fixture imbalances.

We calculated a “strength of schedule” measure, which is an indicator of the underlying strength of each team, absent 2015 draw effects. Today’s post will take that strength measure and apply it to the 2016 draw to analyse

A quick recap

Yesterday we noted that the 2016 season:

  • Creates symmetry in each conference’s external opponents where previously external fixtures were unbalanced, but;
  • Leaves Australian and New Zealand teams with an internally uneven fixture as they play two teams in their own conference twice and two teams once.
  • Causes the additional travel burden to fall mostly on the African teams as well as unavoidably falling most heavily on the Jaguares and Sunwolves.
  • Leaves each conference entirely avoiding one half of the other continent (ie, Africa 1 does not play NZ teams)
  • By preserving intra-country conferences, continues the situation where New Zealand teams face a harder schedule than everyone else due to the strength of their local opponents

We then took a look at the 2015 fixture, already uneven, and noted the impacts the draw had on final standings, especially in that it allowed the Brumbies to qualify at the expense of the stronger Crusaders. We calculated a strength of schedule for each team as shown below:

SRSOS2015

This Strength of Schedule rating will form the basis of our analysis of the 2016 draw, but first we need to take a look at the three new teams.

The Newcomers

The entry of new teams presents a challenge for strength of schedule ratings. With little alternative, we have applied the lines from the Sportsbet total win markets to assign them an assumed strength.

The Jaguares look to be clearly the most formidable new side and a rating of 9 wins based on the betting markets makes them contenders am in their pool (ahead of the Lions and Sharks and way ahead of the hapless Kings).

An indicator of their strength is that the Jaguares have assembled most of the Argentinian national side (the Pumas) save for several of their big guns. The Jaguares are the sort of team Argentina might field in a tour game or World Cup group game against Namibia. Big outs relative to the semifinalist World Cup Pumas squad are:

  • Juan Imhoff (scored 5 tries in the World Cup), Juan Martín Fernández Lobbe (played every game, started 6 of 7) and Juan Pablo Orlandi (played 4 WC games, scored a try) who will remain in France.
  • Marcos Ayerza and Horacio Agulla (1 world cup try) who will remain in England.
  • Tomás Cubelli (played every game, scored 2 tries) who is headed to the Brumbies.

Three of these guys (Lobbe, Orlandi and Ayerza) are 32 or 33 years old and so may be near the end of their careers anyway.

We count 28 players with international experience at the Jaguares, which is well up on most other sides. Despite the absence of a few of their leading tryscorers at international level, not to mention the other core players missing from the 2015 RWC run, their inaugural starting XV will contain 11 (!) players from the semi final. There’s also another 3 RWC semi finalists on the bench, which no other team can boast going into this week.

For comparison, the current All Blacks squad breaks down into nine Crusaders, seven Hurricanes and five Chiefs among others, although the Chiefs also have eight former All Blacks. The Waratahs boast ten current Wallabies (14 total) and the Brumbies nine (12 total). The Bulls have the most current Springboks with seven, although they have another seven former internationals.

Essentially, the Jaguares have around twice as many internationally experienced players as any other team, and they have an edge in recent or current international players as well. That makes them look pretty formidable even if the Pumas are not as strong as the All Blacks or Springboks or Wallabies. Working against them will be the inbuilt permanent and heavy travel load. If they can manage to adjust, they look very strong.

The Sunwolves are a far more motley crew than the Jaguares, with plucky Tier 2 Japan simply not having the national strength of Argentina. We’ve rated them a 2-win team based on the betting markets, and they look very brittle based on squad composition, but they’re also the biggest unknown.

This is what we have gathered to be the composition of the Sunwolves squad:

  • 11 players from Japan’s 2015 World Cup campaign
  • 4 other internationally-capped Japan players
  • 1 tier one foreign international (Tomás Leonardi – Argentina)
  • 3 tier two foreign internationals (Fa’atiga Lemalu and Tusi Pisi from Samoa and Andrew Derutalo from the USA)
  • 4 players with experience in Japan’s U20 side, all previously playing for universities
  • 3 Super Rugby experienced players (Ed Quirk – Reds, Liaki Moli – Blues, Riaan Viljoen – Sharks)
  • 13 players with top level domestic rugby experience in the Japanese Top Rugby or elsewhere such as New Zealand’s provincial competition

The side has had little preparation having been pulled together late, and has only been training together for a short while. Compared to the Jaguares the Sunwolves have less of their nation’s talent pool accumulated in their side. There are seven other Japanese national players dispersed around other Super Rugby teams and two are instead playing in England.

Interestingly, from the Japanese national squad, 12 players are still playing domestic rugby in Japan. This includes nine who played in the World Cup. The group of domestically-signed rather than Sunwolves-signed Japanese internationals includes two World Cup tryscorers who aren’t even playing at the top level in Japan (Karne Hesketh is at second tier Munakata Sanix Blues and Yoshikazu Fujita is at Waseda University).

It’s unclear whether the Sunwolves were unable to secure more Japanese national players in the short window they had, or if they chose not to sign them. We suspect the former and that the Sunwolves have faced a battle with Top Rugby sides to secure the best Japanese league talent.

In terms of their impressive World Cup team’s scoring power, the Japanese cult hero and main goal kicker Ayumi Goromaru instead signed with the Reds. The Sunwolves are also missing the scorers of seven of Japan’s eight World Cup tries.

There are plenty of experienced internationals at the Sunwolves – 18 in all – but only one from a tier one nation. We don’t expect much from them this year, but with more time and preparation, and if they can lure more Japanese internationals in future, perhaps there’s a path to improvement for them in subsequent seasons.

The Kings will just be terrible. We have them as a two win side per the bookies’ projections but even this may be optimistic given sides have gone winless before in Super Rugby. They are essentially a bad provincial South African rugby side.

The Eastern Province Kings, largely the same team as the Super Rugby side, finished 7th in the Currie Cup last year. Of eight teams. They managed to win two games, and were only able to muster up 23 tries across their 10 games.  In the previous Currie Cup, they finished with just one win, anchored to the bottom of the table. They were saved from relegation due to their forthcoming entry to the Super Rugby competition, and the fact that they were an “anchor” team in South Africa.

As far as we can tell they don’t have a single Springbok (past or present), they’ve managed to bring in three players from other Super Rugby sides, two South Africans from France, and another five players from provincial sides other than the Eastern Province Kings. As recently as November they weren’t paying players on time. They’ve also been “taken over” by the SARU from an administrative standpoint. Things are not looking bright for the Kings right now.

Evaluating the 2016 fixture

Having established the Jaguares, Sunwolves and Kings as nine, two and two win teams in terms of assumed strength, we can slot them into our schedule adjusted strength ratings. The results are as follows (some rounding to get the overall competition to 0.500 has been applied):

2016 strength.PNG

We can then use this indicative strength to assess the draw for each team. Let’s start by looking at overall conference strength, since which conference is matched with which has a significant influence over draw difficulty:

SR16 conference strength

This clearly indicates that SANZA(A)R have handicapped their pairings in year one by placing the stronger of each half of the teams against each other.

The New Zealand sides, who collectively project to win 65% of their matches in a fair draw, match up with the stronger (47%) part of Africa, including the Lions, Jaguares and Sharks (and the Kings). The weaker African half (Sunwolves, Stormers, Cheetahs and Bulls), who rate a 41% winning record under a fair draw, get away with a matchup against the 44% Australians.

Put another way, selection of African conference opponents makes a 6% (0.9 win) difference between the Australiasian conferences. But going the other way, the benefit to the African conference of getting Australian opponents over New Zealand opponents is 21%, a full 3.2 win head start.

We can also quantify the internal disparities within each Australasian conference. Below is a chart of who plays double-up games against who (this isn’t an issue in Africa as the intra-conference draw is symmetrical.

intraconference

In New Zealand the Blues have been given the toughest draw through the inescapably bad luck of not getting to play themselves. The hardest possible drawset would be the Highlanders and Hurricanes twice, and nobody cops that double. On the flipside the Crusaders have, by New Zealand standards, a kind draw, avoiding a second match against either of those two toughest teams. The difference between the Crusaders’ draw and the Highlanders’ is about 0.6 expected wins over the season.

In Australia, the Rebels have been handed the easiest possible draw by playing the Force and Reds twice and the Brumbies and Waratahs once. Like the New Zealand conference, nobody cops the toughest double-up of the Waratahs and Brumbies. The Reds come the closest by playing the Waratahs and Rebels twice – the hardest and third-hardest opponents. The difference between the Rebels’ and Force’s opponents is about 0.8 expected wins over the season.

Projecting 2016

Let’s now apply these strengths at the projected results. Remember that the only information feeding into this is 2015 results and an estimated strength for the three new teams:

SR16 proj 1.PNG

On last year’s results, with this year’s draw, we get four of five New Zealand teams qualifying for the finals in spite of draw difficulty, by claiming all three wildcards. This is because compared to last year the Kiwis face less points cannibalism due to more games outside their conference. The Brumbies, facing a tougher draw than last year, get pipped for the third Australasian wildcard by the Crusaders by about 0.6 wins.

In the African side, the Stormers romp to second seed on a very easy New Zealand free schedule, while the Lions win the other conference win leaving the Jaguares to collect the African wildcard entry. The Jaguares, notably, manage this despite being in the tougher group with a lot of New Zealand opponents.

Factoring in luck

When we discussed the 2016 AFL fixture we looked both at what did happen and what might be expected to happen based on probability. One of the variables we looked at was close game luck. Over time, teams tend to lose as many close matches as they win so if they did unusually well one year, that tends to normalise over time and so close game luck can be used to suggest which teams might rise or fall in the standings.

In the case of the 2015 Super Rugby season, here’s what happened in games decided by a single score (7 points or less, excluding the Lions-Stormers draw):

luck.PNG

If luck were to revert to the mean in 2016 and close games were to break even, the Lions would suffer the biggest results slump (winning 3 less) followed by the Hurricanes (2.5 less) and Stormers (1.5 less). The Blues on the other hand would win 2 more games and the Brumbies and Bulls 1.5 more games.

If we insert this normalised luck effect (also adjusting for the season being 15 instead of 16 games long), our updated ladder projections look like this:

SR16 proj 2.PNG

Correcting for their very good run in close games last season, the Hurricanes crash back to, uh, still winning top spot… but lose more than a single game. The Brumbies turning their luck around gets them into the finals as a wildcard at the expense of the Highlanders.

In Africa the significant regression of the Lions leaves the Jaguares to claim their seeded spot, and the Bulls even manage to claim the wildcard on the back of their softer draw.

Conclusion

Remember that the only three things we’ve changed from 2015 in the final projection above is:

  • inserting the new teams with a betting market based strength assumption
  • adjusted for the strength of schedule for each team in 2016 versus the 2015 schedule
  • normalised for luck, assuming each team breaks even in close games rather than achieving the close game split they did in 2015

This of course means we won’t be correct. Teams change personnel, have new injuries, luck breaks differently, tactics are adjusted, and so forth. All we can do is model the future based on insights from the past and be clear that all models are wrong but some models are useful.

We think this model is quite useful in that it shows us the impact of the draw on teams, but also that in the end, close game luck has just as big a role to play. The draw sets conditions, but the draw is not destiny.

We also want to note that while our modelling here illustrates the imbalance inherent in this Super Rugby structure, but this isn’t even really intended to be strong criticism. The tournament is what it is, it’s been designed this way because stakeholders feel that complete draw symmetry is less important to them than other factors like season length, minimising travel and maxmising fan interest. That’s a valid position to take.

There’s changes that could be made but they would all change one of the parameters currently constraining things – we could increase travel loads and reduce fan interest to achieve draw symmetry for instance. we could lengthen the season to achieve it. We could add more teams. We suspect the  tournament will continue to evolve as time goes on.

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The new-look Super Rugby – rebalancing an already uneven fixture #superrugby

The expansion of the Super Rugby to include teams from Argentina and Japan is fascinating from both a football business perspective and for the importance of the growth of the game. In this post we’re going to take a look at the structure of the new competition and then use a strength of schedule approach to analysing draw imbalance in Super Rugby. Tomorrow we’ll focus more on projecting the 2016 season and looking at the newcomers in detail.

Super 18

This year there will be three new teams, bringing the total to 18 and increasing the challenges of fixturing. The basic unit of analysis for the new draw will be two Groups, Australasia (10 teams) and “everyone else” (8 teams – 6 in South Africa along with the Jaguares in Argentina and the Sunwolves in Japan). Each Group is broken into two Conferences – Australia, New Zealand, Africa 1, Africa 2. The Sunwolves are in Africa 1 and the Jaguares in Africa 2. Here’s a diagram of how they match up with each other:

SR2016 structure.PNG

The quid pro quo in setting up the new arrangements is interesting, and are important to understanding the new structure. Essentially South Africa now have their desired 6th team but in exchange have taken on a disproportionate travel burden and lost playoff entry parity. 3 of 8 finals spots will come from the Africa group (ie 37.5% of teams will qualify), and 5 of 10 from Australasia (50%) will make it.

Who plays who

All countries get less intra-country games. Last year everyone played 8/16 games against fellow countrymen. Australia and New Zealand now play 6/15 such “derbies” and South African sides will be playing 7/15.

There’s more travel for everyone. The Jaguares and Sunwolves will obviously have the heaviest travel burden with every trip being long-haul. The Sunwolves even travel to Singapore to play 3 home games. This is a six-hour flight, roughly the equivalent of Perth playing home games in Auckland.

South Africa cops a disproportionate share of the increased travel loads. The South African teams will travel to at least one of Argentina or Japan every season, with trips to both countries every two years. This extra travel is mitigated by the fact that the South African teams play one or two fewer games in Australasia (down from four a season to two or three, depending on home and away balance).

Australasian teams should travel long-haul for just two games as previously, though this may mean two long journeys instead of the traditional extended two-game African leg, for teams going to Argentina or Japan/Singapore as well as to South Africa.

 

Who doesn’t play who

The Super Rugby has never had a fully equal draw due to the constraints of timeframe and geography. However the 2016 schedule has redistributed where the imbalances lie.

Where previously cross-country matchups were uneven (playing 4/5 teams from two other countries), now each team in a country/conference has the same set of external opponents. Each team in Australia plays the same five NZ teams and the same four African teams, and so on.

However, new imbalances have been introduced with important consequences for a playoff structure that seeds conference winners and wildcards.

Firstly, while each African team plays its three conference-mates twice, two return games are missing from within the Australasian schedule. Six games means each Australian side plays two other Australian teams twice, and the remaining two just once. This is significant because the winner of each conference gets top 4 seeding and a home quarter final. The imbalanced draws means some Australian and New Zealand teams have a weaker schedule of opponents than others and an inbuilt advantage in gaining top spot.

Secondly, each conference completely skips a cross-contentinental conference. This year, Africa 1 (the Stormers, Cheetahs, Bulls and Sunwolves) completely skips all the New Zealand teams. We’ll get deeper into conference strength in a moment but suffice it to say that avoiding all NZ teams means a much easier schedule. Since number 1 seed in the finals is decided from among the four conference winners by total points, avoiding the highest quality quarter of the competition gives a South African team a big boost for as long as New Zealand remains a stronger set of opponents.

Thirdly, 15 games means some teams get seven home games and some get eight. In a competition with such long travel, diverse climactic and altitude conditions and parochial crowds, this must be significant. One analysis we’ve read puts the impact of home ground advantage at over a try a game for most teams.

The old competition was not even either

As we mentioned above, the scheduling of teams in the 2015 Super Rugby was not completely even. So criticism of the 2016 format for unevenness must bear in mind that previously, big imbalances existed. (Incidentally, if every team played each other once, in the most plausible completely even draw with eighteen teams, that would be a 17-game season and so there’d still be unevenness in the number of home games each team plays)

Imbalances in 2015 existed in two ways intrinsic to the “8/4/4” matchup structure – teams played more intra-country games than cross-country games, and everyone skipped a team among their set of cross-country opponents. This impacts on the fairness of the competition and we can quantify how much.

Below is a chart of Strength of Schedule, calculated two ways. The first is from the win-loss records of each team’s opponents relative to an even schedule (ie 0.500). The second a measure based on the total season score of all of their opponents, the logic being that the more their opponents scored, the stronger they are, and that high scores are also reflected in bonus points in Super Rugby.

This table illustrates the impacts of the draw imbalance in 2015:

SRSOS2015.PNG

 

The Strength of Schedule compares each team’s opponents to a hypothetical situation of a completely average team playing every other opponent the same number of times. Above 0.500 means a team had a stronger set of opponents than this benchmark, below 0.500 means a weaker set.

The Waratahs and Brumbies had the easiest schedules, with their opponents winning an average of 44.9% of their home games (and the Waratahs’ opponents having slightly less scoring proficiency). This reflects that they only played four games against the stronger New Zealand teams, and that within a weak Australian grouping they did not play themselves. It’s also a reflection of having avoided reasonably strong teams in other countries. The Waratahs skipped the Bulls and Chiefs, both ranked 3rd within their countries, while the Brumbies skipped the Hurricanes (ranked 1st) and Sharks (ranked 4th).

By contrast, pity the Blues whose opponents won 58.6% of their games and amassed the most average points of any team’s set of opponents. Not only did they play four stronger Kiwi teams twice each, but they only avoided the Reds and Sharks, both the second-weakest teams in their countries. Similarly note that the Crusaders were 0.9 wins behind the Brumbies based on draw alone.

We can use this to assess the impact the draw had on the 2015 Super Rugby standings:

expected15.PNG

We can clearly see the impact the draw had on the standings. In reality, the Brumbies made the finals at the Crusaders’ expense by a single bonus point, both having nine wins.

Here, absent the benefit the Brumbies gained by reduced exposure to tough games, the Crusaders (who had the second toughest schedule in 2015) instead make the finals. On total wins, without factoring in bonus points, the Brumbies even fall below the Lions.

Notably, the four strongest teams all turn out to be in New Zealand, with the Waratahs and Stormers only getting second and third instead of fifth and sixth due to the advantageous seed allocated to the country conference winners.

At the foot of the ladder we can see the Blues rising above the Reds on a 2015 fair draw.

Stay Tuned

Above we described the 2016 competition format and noted the imbalances in the draw structure, and then illustrated the impact of an already-imbalanced draw on the 2015 season.

Tomorrow, we’ll bring those two threads together. We’ll quantify just how uneven the four 2016 conferences are, and then use this analysis to make some predictions about 2016. We’ll also spend a little bit of time talking about the newcomers to the Super Rugby and their prospects.

What predictive power do AFL pre-season results have for the regular season? #NABChallenge

Footy is back!

Sort of!

Pre-season trial games have started at obscure ovals where cricket isn’t still getting in the way. It’s a time of great hope, when every team’s draftees and fringe players and returning injured players are showing good signs, and fans and pundits try to identify which teams might have good years by watching each club’s efforts in practice games.

It is a time when the footy press and public relations machine, grateful to have something other than off-field scandal to cover, does its damnedest to sell hope and hype for the season to come. So we’ve decided to take a quick look at how much of that hope and hype is justified.

We have compared preseason and regular season results, compiling the scores from all official NAB Cup, NAB Challenge and AFL-scheduled practice games (including that hilarious 3-way arrangement they ran for a few years), to see how strong the correlation between February and August looks over the last five years:

psvreg1

psvreg2

Yep, with a simple linear trendline, that’s an R² below 15% for both measures. There’s barely a positive predictive relationship in there at all.

There are so many examples of teams blitzing the preseason and then crashing hard, and plenty of premiership and top 4 sides who did nothing in the pre-season. Pre-season form explains nearly none of regular-season form.

We’re not telling you anything new here, but: how your club performs in terms of results in the preseason tells you basically nothing about how the regular season will go and you’re a fool for ever thinking otherwise.