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Why do I do this? Why write articles about selection bias? #MADDAD

Warning: Overly self-indulgent content. After posting an article critiquing the paper McCarthy, Collins, Court (2016) ‘Start hard, finish better: further evidence for the reversal of RAE advantage’ I was called a ‘Mad Dad’ by one of the authors.

Questioning the Underdog Hypothesis #4 McCarthy, Collins & Court (2016). What is ‘the Reversal of RAE Advantage’? Should it continue to be widely referenced?

Summary In most sports, the RAE declines from around mid adolescence as its causes become less relevant. During this decline, over selected early born are deselected at a higher rate than under selected late born.

All you ever need to know about the Underdog Hypothesis in 2 minutes

Relative Age Effects (RAE) are affected by context (e.g. country, sport, gender etc) but a generic RAE timeline in sports with team/squad selection would be: A steady increase from age 5

What does RAE look like in English Women's Cricket

Not significant RAE overall (n=108) BUT… RAE starts high as young players enter professional cricket and then RAE declines… Over the first 10 years of a senior career, Q1 & Q2 appear to decrease with an increase in Q4 occurring…

Does early maturation offer the same advantage for girls as it does for boys in player evaluation & selection?

Recent evidence has shown that maturation in girls may have a different and more complicated narrative than boys. For boys, earlier maturation increases muscle mass, giving significant advantages of power, speed and endurance over later maturers.

The topsy-turvy world of National Counties cricket.

2023 saw a fabulous victory for Buckinghamshire over Devon in the National Counties Championship final. This historic competition, first played in 1895, is as English as cake and Alice in Wonderland.

How to best use Age Ordered Numbered Bibs in cricket development.

Background: How Age Ordered Numbered Bibs reduce RAEs in youth football The ECB recently teased two videos on the coach development platform @icoachcricket covering Relative Age Effects and maturation selection bias.

The cumulative & opposing effects of RAEs and maturation selection bias for both boys & girls?

Relative Age Effects 101; Maturation selection bias 101 Who are the most overly selected groups in cricket pathways and who are the most under selected? Does it differ for boys and girls?

An investigation of the senior RAEs timeline of four male professional English sports.

HYPOTHESIS That RAEs will knock-on from junior levels into the early years of senior sports and continue to decline, possibly to a point where RAEs reverse. METHOD A snapshot of the 2021/2022 season was taken for male English football, cricket, rugby union (RU) and rugby league (RL), (n=1120, avg Age=26.

Selections for England Men’s Lions. It’s all about the journey.

If you are one of the 21 man squad for the upcoming England Lions training camp how did you get there? The 3 week camp, for red ball skills, has a mix of players, from Rehan Ahmed at age 19 to Brydon Carse at 28.

No England U17 team planned, says ECB. So what is happening instead?

In a recent article I questioned the risk/benefits of reintroducing an England U17 programme, a recommendation of Andrew Strauss’s High Performance Review. Issues of growth & maturation bias, return on investment and alternative options such as an U19 Futures team were discussed.

Should we be re-instituting an England U17 cricket team?

HEADLINES ECB run matches for 15s/16s at Loughborough this month Maturational selection bias and Relative Age Effect are high at these ages History of promoting early developers to fail Poor ROI for previous U17 programmes

How to trial Age Ordered Bibs to reduce RAEs in cricket

INTRODUCTION Mann & Ginneken (2017) successfully used Age-Ordered Numbered Bibs in football to address Relative Age Effect. This is a summary of what a similar intervention in cricket would look like.

What happens if the people who benefited from the system are in charge of the system?

Students from the University of Pennsylvania recently took part in an interesting experiment. In answering a spurious questionnaire about the factors that may have helped them to the Ivy League, the students inadvertently provided the single most important data point at the top of the page.

Competition Level Effects in English Women & Girls National Cricket Pathways

Highlights Extraordinary levels of RAEs within the women’s national pathway RAEs increase with every stage of the women’s national pathway RAE Reversal in current national senior squad  Perhaps, shorter formats (T20) favour early born.

Women’s Cricket. A Game For Me?

The professionalisation of English Women & Girls cricket is developing fast under the tagline of cricket - a game for me. But is it really a game for everyone? Does this welcome expansion come with hidden issues that are also present in the men’s game?

Unnatural Selection: The Myths and Misconceptions of Relative Age Effects and Maturation Biases.

Every young cricketer has a fair chance of becoming a professional, right? Unfortunately, this suggestion does not reflect the reality of everyone’s opportunities in cricket. In fact, as well as recently debated racial and socioeconomic factors, two other things can considerably affect your chances: the month of your birth (i.

RAEs Profile of English Women’s U19 WC Squad not reflective of that in The Hundred

93%* of the English Women’s U19 World Cup squad 2023 (n=15) are born in the first half of the year. No Relative Age Effects (RAEs) are found across the English women players in the eight teams of The Hundred 2022 (n=91).

Age is a protected characteristic: ECB EDI Training

The ECB have produced an excellent EDI online training module for recreational cricket. This is, in part, a response to recent findings of racism in cricket as discussed by the DCMS committee for example.

How does the RAE Profile of English Rugby Union internationals compare with the source cohort in the English Premiership?

Highlights Junior RAE knocks on to the English Premiership (EP) in Rugby Union No RAE in England Internationals (2003-2022) RAE continues its decline in senior Rugby Union (EP) until age 30

10 things that require zero talent

If you have benefited from one or more of the systemic biases below you probably won’t buy into the message. If you’re unaffected, you’re unaffected.

RAE profile of England World Cup squad accurately reflects that of English Premier League players.

The Relative Age Effect (RAE) profile of professional team sports is often assumed to be even (i.e. all 4 Birth Quarters are more or less level) and that RAE is only found in youth development.

Rise of the underdog or fall of the top dog? A study of Canadian Ice Hockey stats from Gibbs et al, 2012

Gibbs’s hypothesis, from 2012, of an underdog effect is often referenced in many papers relating to investigations into Relative Age Effects (RAEs). The hypothesis is used to explain how levels of RAE fall over time from a peak during adolescence to either a lower RAE, parity, or a RAE reversal at some point in a senior career.

How do Relative Age Effects in Junior Pathways change into the absence of RAEs in Senior Professional Cricket?

Highlights RAE is carried over from junior pathways into (18+) professional cricket RAE quickly declines through the Rookie phase (18-24) RAE has reversed at the Prime phase (25-29) If you measure the entire senior cohort of professional cricketers in England & Wales there is no overall Relative Age Effect, i.

Andrew Strauss, HPR & a reinstated England U17s?

One proposal in Andrew Strauss’s High Performance Review is to reinstate the England U17 programme to provide ‘early international benchmarking’. While this will provide increased opportunities to experience overseas conditions, selecting and investing resources into players at this age does come with some drawbacks.

Questioning the Underdog Hypothesis #3 Ford & Williams

What is the Underdog Hypothesis and why question it? Ford & Williams (2011) A study of 205 award winning (e.g. MVP, Ballon D’Or) male athletes from football (FIFA & UEFA), ice hockey (NHL), baseball (MLB) and Aussie rules football (AFL), from between 1987 and 2007.

Questioning the Underdog Hypothesis #2 Fumarco, Gibbs, Jarvis, & Rossi

What is the Underdog Hypothesis and why question it? Fumarco, Gibbs, Jarvis, & Rossi (2017) A study, by birth quarter, of scores and salaries of drafted Canadian and USA National (Ice) Hockey League (NHL) professionals (not goalies), from the 2008–2009 season to the 2015–2016 season.

Questioning the Underdog Hypothesis? An introduction

Why are we questioning the Underdog Hypothesis The Underdog Hypothesis (UH) suggests that later born players benefit from greater challenge during development because they are training/playing with relatively older peers. Gibbs, Jarvis & Dufur (2012) when studying ice hockey stated ‘relatively younger players are thought to benefit by more competitive play with their older counterparts’.

Questioning the Underdog Hypothesis #1 Gibbs, Jarvis & Dufur (2012)

What is the Underdog Hypothesis and why question it? #1 Gibbs, Jarvis & Dufur (2012) A study of RAE in male Canadian born National (Ice) Hockey League (NHL) professionals and those (the best) that played for the annual All Stars team and Olympic squads.

Relative Age Effects in Male Cricket: A Personal Assets Approach to Explain Immediate, Short-Term, and Long-Term Developmental Outcomes

This was a longitudinal study (n=1800) of English male cricketers from Regional U15 thru to International with up to 20 years of data, using the Personal Assets Framework (PAF) to examine immediate, short-term and long term outcomes.

Paper Published

Relative Age Effects in Male Cricket: A Personal Assets Approach to Explain Immediate, Short-Term, and Long-Term Developmental Outcomes www.mdpi.com/2075-4663/10/3/39/htm

How Goldilocks beats David & Goliath. A look at the Underdog Effect in English Cricket

Highlights: In international cricket, male English later borns DO NOT do better than early borns. In general middle born (Q2 & Q3) do better with the following exceptions: Q4 best for Test bowling

What format do Q1 English male batters excel at? The shorter the better?

In the current T10 League in Abu Dhabi there are 18 English & Irish male batters (some are all rounders). An incredible 61% are from Birth Quarter 1 (Sep-Nov). Are Q1 batters more suited to shorter formats?

Do late born players really excel in elite cricket? Part 3. Does Country matter?

Is there a later born bias in Test cricket all around the world? Quick answer, No. Background: Relative Age Effect, Underdog Effect, Birth Quarters. This article is part of a series ( Part 1 (Test) & Part 2 (All Formats)) looking at if later born players excel in international cricket.

Why it’s important to consider a maximum Conversion Rate!

Conversion Rates (CR) have been used in the research to highlight how later born players (Q3 & Q4) are more likely to transition to the next step in a development pathway or indeed to reach international levels.

How to compare Birth Quarter % data - Caps or Runs/Wickets?

Player % v Match % Just counting the number of players in a Birth Quarter out of a cohort values them equally. Using the percentage of all matches played by the cohort gives a weighting to the very best and vice versa.

68 Guns: No not The Alarm but male England Test Players with 50+ Caps

Highlights: Q1 Batters under-represented at only 16% (n=51) Q4 Bowlers over-represented at 41% (n=22), equally split between Fast and Spin Later borns are over-represented at 57% (n=68). The more caps the higher the later borns representation (65% for caps 166-95, n=17)

Aussie Test Best v Best: How many Q1s? How many Q4s?

After eating too much cheese I had a bad dream, where the 22 most capped Aussie Test players played a match. Here were the teams: What is surprising is that the (Little) Rippers XI are ALL Q4s.

Do late born players really excel in elite cricket? Part 2. Is Format relevant?

Background: Relative Age Effect, Underdog Effect, Birth Quarters. In Part 1, which covered Test cricket only, we found mixed evidence for the notion that late born cricket players excel at super-elite levels.

Do late born players really excel in elite cricket? Part 1.

Background: Relative Age Effect, Maturation Bias, Underdog Effect, Birth Quarters. It seems to be widely accepted that late born and/or late maturers reach higher levels of elite performance in cricket. For example, Tim Wigmore, in his 2020 book ‘The Best: How Elite Athlete Are Made’, states 64% of male Test players with over 50 caps are born between March and August (Q3 30%, Q4 34%).

Individual Thinking v Systems Thinking

In a data rich sport like cricket we try our best to make informed decisions but do we underestimate the influence of perspective? Take this following example when looking at Birth Quarter effects.

10 Relative Age Effect (RAE) Myths

Background: What is Relative Age Effect? What are Birth Quarters? 1. This is just about Q1s and Q4s Q2 and Q3 are important too! In cricket there tends to be a difference between Q1/Q2 and Q3/Q4 (also known as H1 and H2 for Half-Year).

Possible Fixes for Relative Age Effect in Cricket

Relative Age Effect (RAE) exists in male and female cricket as well as many other sports and non-sporting areas of life. Here is a list of some of the possible ways to reduce or remove the systemic bias and discriminatory effects of RAE.

Is Maturation currently the biggest unaddressed issue in Player ID & Development in English Cricket?

Inter player differences in maturation can be at least 5 years (Figure 1) whereas Relative Age Effects (RAE) are only up to 1 year (1). In development environments the magnitude of the effect of these differences can be up to approximately 10-fold (2).

[What is] the Galatea Effect

The Galatea effect is essentially if a player thinks and believes they can succeed they will succeed and vice versa. It’s about confidence in one’s own ability and the feeling of destiny.

[What is] the Pygmalion Effect

A phenomenon within the coach-player relationship whereby if a coach has high expectations of a player then the player is more likely to fulfill those expectations. The effect is described as also working in reverse.

Is the Relative Age Effect Discrimination?

Discrimination is defined as the unjust or prejudicial treatment of different categories of people, especially on the grounds of race, age, sex, or disability. So to treat someone prejudicially on the basis of their age is discrimination.

Is a Selection Concentration Effect a large part of the Underdog Effect?

A number of studies have shown how later born and/or later maturing players do better out of the development process. This can be shown through higher percentages of these players reaching international levels for example (1).

Relative Age and Maturation Effects Are Separate Constructs

Differences in youth maturation between players can be up to 5 or 6 years. Relative Age Effect, although significant, only has a maximum of 1 year inter-player variance. Most of the articles on this blog have dealt with Relative Age Effect alone simply because I only have access to Date of Birth data.

[What Is] Maturity Timing

Maturity Timing is different to Maturity Status. A player’s maturity timing can be classified as Early, On Time or Late. Typically 15% are Early and Late with 70% On Time.

Are we scared to lose the Underdog Effect?

Warning: More ‘Discussion piece’ with assumptions. In the girls cricket pathway Relative Age Effect (RAE) is weaker than the boys pathway (assumption, no evidence?) yet there appears to be a significant RAE Reversal (RAER) in senior cricket.

Why do later born players have longer careers for England Women in T20 cricket?

In T20 cricket we select slightly more early born England Women yet late borns have careers almost twice as long. In general there is a Relative Age Effect in women’s sport pathways but it is often less significant than in men’s sport.

Matches played by Birth Quarter

Much research has been conducted on the Relative Age Effect over many decades. Virtually all of it (perhaps all?) collects data based on the Birth Quarter percentages of players who have played a particular sport over a period of time.

Darwin, Skiing, Chess & 250,000 Swedes.

What has Darwin got to do with X-Country Skiing, Alpine Skiing, Call of Duty, Chess and almost 250,000 Swedes? A recent paper from researchers at Umea University in Sweden looked at how younger athletes fare in individual sports for both physical and non-physical sports and across most age groups and both sexes.

How to Build an England Cricketer

Warning: This is a little ‘tongue-in-cheek’. Be born in the last half of the year, preferably August. Be a late maturer. Probably best not to join a pathway too early - too much formal/boring practice.

How to Build a (Professional) Cricketer

Warning: This is a little ‘tongue-in-cheek’. Be born in the first half of the year, preferably September. Be an early maturer. Have taller than average parents. Have older siblings that play cricket.

Relative Age Effect in Men’s Cricket Pathway (U15-U19)

Relative Age Effect is found at U15, U17 and U19s in the Men’s cricket pathway. Birth Quarters Q1 & Q2 are found to be much higher than Q3 & Q4 at each stage of the pathway.

RAE at Bunbury (Regional U15s)

Bunbury is an annual event, held at a private school, for the four regions at the U15 age group, and has run for over 30 years. The South & West, London & East, the North and the Midlands compete in 3 50 over matches and 2 T20 matches each.

RAE at Super 4s (Regional U17s)

The Super 4s is an annual event, held at Loughborough, for the four regions at the U17 age group. Having run for the last seven years, the South & West, London & East, the North and the Midlands compete in 3 50 over matches and 2 T20 matches.

[What Is] The Matthew Effect

In a development environment when hidden talents are missed by coaches and only the obvious, visible ones are valued is an example of the Matthew Effect. It is also used in the context of ‘the rich get richer while the poor get poorer’ so when coaches spend more time with players they can see value in then this develops a positive feedback loop for that player.

[What Is] The Younger Sibling Effect?

When growing up a younger sibling playing with an older, stronger, faster & better older sibling/siblings will benefit from having to ‘battle’ and constantly find ways of dealing with the heightened challenge.

The Underdog Hypothesis & Starting Quality

It has been found that later born ( BQ 4) players reach higher elite levels than early born (BQ 1) players in many sports such as NHL, Rugby Union and Cricket.

[What Is] Maturity Status

Maturation is the onset of the adolescent growth spurt. Maturation Status is either how far an individual is away from it, how far through it, or how far after it they are.

Age-ordered shirt numbering fixes Relative Age Effect & Maturation Bias during trials

One of the ways to address the Relative Age Effect (RAE) found in cricket is to use age-ordered shirt numbering in trials. Trials in cricket are ubiquitous. Often numbered bibs are used during trials to aid identification.

Is the Underdog Effect overrated?

In cricket, as in many sports, more elite players are later born than early born. For example, Q3/Q4 players have longer England ODI careers (+30%) than Q1/Q2 players, yet more Q1/Q2 players are selected.

[What Is] The Underdog Effect

A number of research articles have shown that those players born in Birth Quarter 4 (Q4 June-August) and to a lesser extent in Q3 (March-May) are more likely to reach higher levels within cricket (and other sports such as Rugby and Ice Hockey) than those born in Q1 or Q2 (between September and February).

The [What Is] Series

Birth Quarter Galatea Effect Matthew Effect Maturity Status Maturity Timing Pygmalion Effect Relative Age Effect Underdog Effect Younger Sibling Effect

[What is] Birth Quarter?

Birth Quarter is the 3 month period that some is born in within a single academic year. For the UK this will be: Quarter 1 (Q1) : September-November Quarter 2 (Q2) : December-February

[What is] Relative Age Effect?

Whenever there is a cut-off date such as 31st August in any single year environment such as a UK school year or cricket age group then those that are born close after it have significant advantages in terms of higher levels of selection, participation, opportunity and coaching.

Relative Age Effect in Women’s Cricket (England ODI selection)

Since 2001 Q3/Q4 England Women ODI players have played TWICE as many matches as Q1/Q2 players. In Women’s cricket RAE appears to be reversed. Q3/Q4 players are selected more than Q1/Q2.

Learning to Win v Winning to Learn

I advocate Equality in Cricket. The One More Summer website exists to help achieve equality of opportunity for ALL and not just those born in the first half of the academic/sporting year.

Some Counties Are ‘RAE’ Better Than Others

Recent articles have shown significant Relative Age Effect in England U19s & county U20s and how the RAE profile reverses from age 25 in county squads. Within these statistics there is quite a lot of variation between counties.

How we can fix RAE and Maturation issues in English Cricket

Why should we care about this? We should recognise it’s UNFAIR. All sports should have Equality of Opportunity. It’s COUNTER-PRODUCTIVE. Elite players are derived from a reduced player pool. It’s INEFFICIENT.

How RAE Affects a County Career

There is no significant Q1/Q2 bias in County Squads. But there is significant Q1/Q2 bias as players start their careers which is then REVERSED from the age of 25. No significant impact from Overseas players.

Do England ODI players born early or late debut at different ages?

No. Not really. Sept-Oct born (Q1) are slightly older. Q1 and Q4 (Jun-Aug) have more variation in ages. Q1 has both the youngest (19) and oldest (36) players. 4 of 5 players to debut over 30 were Q1.

Part II: Evolution of the Fittest?

England One Day International (ODI) Fast Bowlers born between September and February have SHORTER careers than those born between March-August but we pick MORE of the former. ODI Batsmen born between September and October are the most selected Birth Quarter yet play FEWER matches than those born between November and May.

Do we have a Relative Age Effect in cricket?

Yes. Research has shown Relative Age Effect (RAE) in the English and Australian cricket player pathways. In 2015 Ed Barney (2) from Bangor University, in working with the ECB, looked at RAE in English cricket as part of his PhD.

RAE Increasing in England U19 World Cup Squads

Young Lions (U19) World Cup squad players born between September and February are twice as likely to be selected than those born between March and August. A preference for selecting players born earlier in the academic/sporting year is a well known and researched concept called Relative Age Effect (RAE).

Part I: But we’ve just won a World Cup!

England One Day International (ODI) players born between September and February play fewer matches over a career than those born between March and August, but are selected more often. A little background …