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Introduction Introduction

Props 1,3

Hooker 2

Locks 4,5

Blindside Flanker 6

Openside Flanker 7

Number 8 8

Scrum Half 9

Fly Half 10

Centre 12,13

Wing 11,14

Full Back 15

Glossary

How the RPI

scoring works We have built a revolutionary rugby rating system based upon individual skill executed in real time in partnership with leading academics and sports professionals from around the world. Our approach is all about winning, and the contribution to winning. We’re dealing with professional sports people – it’s not about participation and making up the numbers. Our research shows that a decent team rating system beats popular opinion. More importantly, a team rating combining individuals beats the best team rating systems. Winning a game is about winning moments – quantifying this impact provides an even richer perspective of behaviour. This approach points us in a unique position as we can say that V is the most valuable player now, with an individual rating of W, because they rate high on X and Y which improves their team’s chances of winning by Z%. We now know that to win games in an elite rugby environment, key moments in a game need to be won. Using a combination of demand forecasting, survival analysis and concepts from statistical process control, we have been able to quantify the impact of moments on an overall outcome. Importantly, our approach is focused on winning. That is, what does it take to win? The emphasis on winning and predictivity ensures we obtain parsimonious models that are aligned with perception and are more readily interpretable and as a consequence, defendable. For instance, when we compared a team rating system for teams combining individual ratings with a team rating based only on team performances we obtained a 13% improvement in predictivity. As we usher rugby audiences into a new era of appreciating the game through informed analytic insight, we need to build trust. Our framework, geared around moments, in real time lends itself to a transparent framework. Importantly, as we expand on team ratings using individuals we are in a strong position to understand and compare competitions, due to relative performance and depth of talent. We can also expand this to comparing generations, positions, partnerships, coaches to name a few issues that consumers would find interesting. We are constructing an expert system. That is using a combination of machine learning, shaped by winning outcomes and guided by human observers, we are creating a dynamic system that will output meaningful, rugby orientated output that will stimulate, engage and challenge thinking of those interested in rugby across all levels.

Prop A RPI prop is the champion of their team's scrums and lineouts. The best can set up an ordinary contest for game-winning moments. The following factors distinguish the RPI prop from his fellow forward pack: Influence RPI uses an 'Influence' score to measure the effect a prop has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it is a losing moment, RPI will punish them for it. Scrum Score As the powerhouse of the forward pack, props deliver the strength to win scrums. RPI uses ‘Scrum Score' to measure a prop's scrum ability. If a forward pack turns the ball over from a scrum, the prop's player rankings grow. Conversely, if a forward pack loses possession from a scrum, the prop's player rankings suffers. Lineout Score Jumpers at lineouts require a steady lift to collect and steal the ball. RPI uses ‘Lineout Score' to weigh-up a prop's impact on lineouts. If a jumper wins a lineout from an opposition throw, the prop's player ranking rises. Equally, if a jumper loses a lineout thrown by their own team, the prop's player ranking pays the price. Standard Factors In addition to the prop's distinguishing RPI factors, they share some RPI factors with other positions. These factors are crucial for any top rugby player. Carry Metres

Line Tackle

Other Tackle

Missed Tackle

Hooker The best RPI hookers are rock solid. Consistent and reliable, their teams trust them to throw lineouts straight and true every time. In the scrum and on defence, they'll never shirk from putting in work. The following features distinguish the hooker from his fellow forward pack: Influence RPI uses an 'Influence' score to measure the effect a hooker has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it is a losing moment, RPI will punish them for it. Lineout Score Hookers are the specialist responsible for throwing the ball at the lineout. RPI uses 'Lineout Score' to weigh-up their impact on these set pieces. If a jumper wins a lineout from an opposition throw, the hooker's player ranking rises. Equally, if a jumper loses a lineout thrown by their own team, the hooker's player ranking pays the price. Scrum Score Hookers keep or turn over possession with their feet in the scrum by ‘hooking' the ball. RPI uses ‘Scrum Score' to measure this crucial role. If a forward pack turns the ball over from a scrum, the hooker's player rankings grow. Conversely, if a forward pack loses possession from a scrum, the hooker's player rankings suffers. Jackal Not only are RPI hookers critical at the lineout and the scrum, but the best will turn the ball over from grounded players. The Jackal score measures their ability to win possession from a tackled player, by collecting the ball from a grounded opponent while on their feet. Every time a hooker completes a successful Jackal, their player ranking climbs. Standard Factors In addition to the hooker's distinguishing RPI factors, they share RPI factors with other positions. These factors are crucial for any top rugby player. Attacking

Carry Metres

Line Tackle

Other Tackle

Pick and Go Metres

Snaffle

Missed Tackle

Locks Top RPI locks will dominate the lineout. Regardless of who throws the ball in, they'll win it. The following features distinguish the lock from his fellow forward pack: Influence RPI uses an 'Influence' score to measure the effect a lock has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it is a losing moment, RPI will punish them for it. Lineout Take The main priority for a lock is to catch balls thrown by their own hooker. RPI uses the 'Lineout Take' score to measure the effectiveness of a lock at managing these lineouts. Each time they successfully catch a lineout ball thrown by their own team, their player ranking improves. Lineout Steal The best locks won't just take their own lineouts – they'll win their opposition's too. The 'Lineout Steal' score measures a lock's ability in hostile lineouts. A lock's player ranking increases whenever they catch a lineout ball thrown by the opposition. For each successful steal, their player ranking grows. Lineout Score RPI uses 'Lineout Score' to weigh-up the lock's wider impact on lineouts. If any jumper wins a lineout from an opposition throw, the lock's player ranking rises. Equally, if any jumper loses a lineout thrown by their own team, the lock's player ranking pays the price. Standard Factors In addition to the lock's distinguishing RPI factors, they share RPI factors with other positions. These factors are crucial for any top rugby player. Attacking

Carry Metres

Line Tackle

Other Tackle

Pick and Go Metres

Scrum Score

Missed Tackle

Blindside Flanker RPI blindside flankers are the true utility player. The best blindside flankers are experts at turning the ball over at breakdowns, and influence the game at confrontational moments. The following factors distinguish the RPI blindside flanker from his fellow forward pack: Influence The Influence score is a way RPI measures the effect a flanker has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it's a losing moment, RPI will punish them for it. This means that the special features of a players game is not lost. Jackal RPI blindside flankers turn the ball over at every opportunity. The Jackal score measures their ability to win possession from a tackled player, by collecting the ball from a grounded opponent while on their feet. Every time a blindside flanker completes a successful Jackal, their player ranking climbs. Tackle Turnover Each time possession is turned over as a result of a blindside flanker's tackle, their player ranking increases. Snaffle When a blindside flanker collects a loose ball in open play, RPI measures a 'Snaffle' score. The 'Snaffle' score assesses the blindside flanker's handling and positioning. The more they snaffle, the better their player ranking. Standard Factors In addition to the blindside flanker's distinguishing RPI factors, they share some RPI factors with other positions. These factors are crucial for any top rugby player. Carry Metres

Line Tackle

Lineout Score

Lineout Steal

Lineout Take

Missed Tackle

Other Tackle

Pick and Go Metres

Scrum Score

Openside Flanker While as much of a utility player as the blindside flanker, RPI openside flankers step away from the lineout - and instead focus their attention on game-winning decision making. The following factors distinguish the RPI openside flanker from his fellow forward pack: Influence The 'Influence' score is a way RPI measures the effect a flanker has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it's a losing moment, RPI will punish them for it. This means that the special features of a player's game is not lost. Jackal RPI openside flankers turn the ball over at every opportunity. The Jackal score measures their ability to win possession from a tackled player, by collecting the ball from a grounded opponent while on their feet. Every time an openside flanker completes a successful Jackal, their player ranking climbs. Snaffle When an openside flanker collects a loose ball in open play, RPI measures a 'Snaffle' score. The 'Snaffle' score assesses the openside flanker's handling and positioning. The more they snaffle, the better their player ranking. Tackle Turnover Each time possession is turned over as a result of an openside flanker's tackle, their player ranking increases. Standard Factors In addition to the openside flanker's distinguishing RPI factors, they share RPI factors with other positions. These factors are crucial for any top rugby player. Attacking

Carry Metres

Line Tackle

Other Tackle

Pick and Go Metres

Scrum Score

Missed Tackle

Number 8 Top RPI number 8s are their team's secret weapon on both attack and defence. Their passing, running, and tackling makes them the ultimate asset. The following factors distinguish the RPI number 8 from his fellow forward pack: Influence The 'Influence' score is a way RPI measures the effect a number 8 has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it's a losing moment, RPI will punish them for it. This means that the special features of a player's game is not lost. Pass Complete In unison with the half back, RPI number 8s use their expert distribution to create game-winning moments. The 'Pass Complete' score measures successful passes. Each time the number 8 completes a successful pass, their player ranking increases. Scrum Score Managing direction and distribution at the helm of the scrum, number 8s are a crucial element to any successful forward pack. RPI uses 'Scrum Score' to measure a number 8's scrum ability. If a forward pack turns the ball over from a scrum, the number 8's player rankings grow. Conversely, if a forward pack loses possession from a scrum, the hooker's player rankings suffers. Attacking RPI uses a group of measurements to assess a number 8's attacking ability. Each line break, defender beaten, and successful offload will improve a number 8's player ranking. Standard Factors In their role as the bridge between forwards and backs, RPI number 8s are measured on diverse criteria: Carry Metres

Line Tackle

Lineout Score

Lineout Take

Other Tackle

Missed Tackle

Scrum Half The best RPI scrum halves are the craftiest players on the field. Their passing is second to none, knowing exactly what to do with the ball – and when. The following factors distinguish the RPI half back from the rest of the back line: Influence The ‘Influence’ score is a way RPI measures the effect a half back has on their team’s likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it’s a losing moment, RPI will punish them for it. This means that the special features of a player’s game is not lost. Pass Complete As the link between the forwards and the backs, the best scrum halves have formidable handling and distribution. The ‘Pass Complete’ score measures successful passes. Each time the scrum half completes a successful pass, their player ranking increases. Territorial Kick Metres In their critical role at the back of each breakdown, the best scrum halves know when to kick for territory. RPI measures this with a ‘Territorial Kick Metres’ score. The more metres gained from a scrum half’s kick, the higher their player ranking. Standard Factors In addition to the half back’s distinguishing RPI factors, they share RPI factors with other positions. These factors are crucial for any top rugby player. Attacking

Carry Metres

Line Tackle

Other Tackle

Scrum Score

Fly Half Top RPI fly halves are the brains of the bunch. They nail penalties and conversions, gain precious metres from territorial kicks, and create game-winning moments. The following factors distinguish the RPI fly half from his fellow back line: Influence The 'Influence' score is a way RPI measures the effect a fly half has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it's a losing moment, RPI will punish them for it. Every positive touch of the ball leading to gained territory or points on the board increases their ranking. Goal Success Most fly halves are responsible for kicking penalty goals and try conversions1. RPI measures their ability to accurately strike the ball with the 'Goal Success' score. For every successful penalty or conversion kick, a fly half's player ranking will increase. Attacking The best fly halves read the play and are often the inspiration for attacking plays. RPI uses a group of measurements to assess a fly halves attacking ability. Each line break, defender beaten, and successful offload will improve a first five's player ranking. Territorial Kick Metres Given their ability to kick the ball with precision and power, fly halves are effective at using their boot to gain territory. RPI measures this with a 'Territorial Kick Metres' score. The more metres gained from a fly half's kick, the higher their score. Standard Factors In addition to the first five's distinguishing RPI factors, they share some RPI factors with other positions. These factors are crucial for any top rugby player. Carry Metres

Line Tackle

Missed Tackle

Other Tackle 1 Non-kicking fly halves are still rewarded be the Influence score.

Centres Top RPI centres are workhorses. By running attacking lines and making crunching tackles at the defensive line, they are often the difference between a winning moment and a losing one. The following factors distinguish the RPI centre from the rest of the back line: Influence The 'Influence' score is a way RPI measures the effect a centre has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it's a losing moment, RPI will punish them for it. This means that the special features of a player's game is not lost. Attacking The best centres turn each offensive moment into a game-changing result. RPI uses a group of measurements to assess a centre's attacking ability. Each line break, defender beaten, and successful offload will improve a centre's player ranking. Break RPI uses a 'Break' score to specifically measure metres gained from line breaks created by a centres offensive ability. The more metres gained from a break, the higher the centre's player ranking. Standard Factors In addition to the centre's distinguishing RPI factors, they share RPI factors with other positions. These factors are crucial for any top rugby player. Carry Metres

Other Tackle

Missed Tackle

Wings Needless to say, the best RPI wingers are fast, strong, and smart. They are renowned for their ability to turn a high ball into a game-winning moment. The following factors distinguish the RPI winger from the rest of the back line: Influence The 'Influence' score is a way RPI measures the effect a winger has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it's a losing moment, RPI will punish them for it. This means that the special features of a player's game is not lost. Attacking As the last man in most offensive plays, the winger plays a critical role in creating game winning moments. RPI uses a group of measurements to assess a winger's attacking ability. Each line break, defender beaten, and successful offload will improve a winger's player ranking. Territorial Kick Metres Wingers are often responsible for returning opposition clearance kicks. RPI measures this with a 'Territorial Kick Metres' score. The more metres gained from a winger's kick, the higher their player ranking. Try Saver To measure a winger's critical tackling ability, RPI uses a 'Try Saver' score. Each time a winger makes a successful tackle as the last line of defence, RPI increases their player ranking. Standard Factors In addition to the winger's distinguishing RPI factors, they share some RPI factors with other positions. These factors are crucial for any top rugby player. Break

Carry Metres

Defensive Catch

Line Tackle

Mark

Other Tackle

Fullback Top RPI fullbacks are gritty players, with pace and a powerful boot. As the last line of defence, the RPI fullback is a try-saver. Comfortable under the high-ball, top RPI fullbacks can turn games around within split seconds. The following factors distinguish the RPI fullback from his fellow back line: Influence The 'Influence' score is a way RPI measures the effect a fullback has on their team's likelihood of winning. If they are involved in a play 2 minutes prior to a winning moment, their player ranking climbs. Conversely, if it's a losing moment, RPI will punish them for it. Try Saver To measure a fullback's ability as their team's last defender, RPI uses a 'Try Saver' score. Acknowledging the critical role of the fullback in defending when the opposition breaks the line, each time a fullback makes a successful tackle as the last line of defence, RPI increases their player ranking. Fielding Kicks Mark A player (usually a fullback) can call 'mark' when they catch the ball behind their own twenty-two metre line, preventing opponent players from tackling them, and giving their team a free kick. RPI measures a fullback's strategic catching ability with the 'Mark' score. Each time a fullback successfully calls a mark, their player ranking climbs. Defensive Catch RPI measures a fullback's ability to compete for, catch, and manage a high ball with the 'Defensive Catch' score. Each time a fullback makes a clean defensive catch (where the opposition makes the kick), their player ranking improves. Standard Factors In addition to the fullback's distinguishing RPI factors, they share some RPI factors with other positions. These factors are crucial for any top rugby player. Attacking

Carry Metres

Line Tackle

Missed Tackle

Other Tackle

Territorial Kick Metres

ELO Team Rankings The Elo rating system, originally developed for chess, is increasingly being applied to mainstream sports. Here it is used to derive team ratings and predict match outcomes for international and domestic rugby union tournaments. Two modifications are proposed to improve the performance of the Elo system in this setting. The high scores typical in the modern game of rugby allow us to replace the binary win/loss match outcome with a points ratio bounded between zero and one. We show how this modification makes ratings trajectories both more stable and more accurately reflective of performances. Secondly, accurate initial ratings are efficiently determined by constrained optimisation on a small training set. We also account for home ground advantage, which is an important factor in rugby. Once ratings trajectories have been computed, a logistic model is trained to predict win/loss outcomes from ratings differences. The Elo learning rate k and lasso regularisation parameter C are then optimised for predictive performance, using a cross-validation scheme which respects the time structure of the match schedule. Finally, a novel interpretation of the learning rate k is proposed.