How good will a player be?
I recently read an article by 21st club, asking the question: "How good will De Ligt be?" Predicting the development of a player or an employee is arguably one of the hardest tasks in football as it is in business. There are simply too many factors that can influence the development and make every prediction obsolete within a few seconds.
However, despite the difficulties, we can approach an estimate by taking the question apart. We can do this by first calculating what Kahneman calls “the outside view” and put the problem into comparative perspective that ignores its uniqueness. Subsequently, we can zoom in into De Ligt’s particular case and use all the details we can acquire to adjust the percentage up or down to estimate his potential. In the book Superforecasting, this process is called Fermi-zing.
Outside View
Let’s start and pack the question into components, starting with the status quo:
1. How good is De Ligt currently and how old is he?
De Ligt currently has a rating of X and he is 19.9 years old. For facilitation purposes, let’s just say he is 20 and take his Football Manager rating from 2020 which was 77.
2. When do players usually reach their peak?
Before we answer this question, we have to define the target group that we’re evaluating. Here, we have different options:
Player development in general
Player development of centre-backs
Player development of the top 50 <= 21
…
In their article, 21st club refer to the development of the top 50 aged 21 or younger. However, the sample size is arguably too small to use as a base rate. Therefore, we decide to focus on the development of centre-backs in general. According to 21st club, players usually peak between 25-28. This in line with the findings of Dendir (2016) and Kalen et al. (2019), who point out that defenders peak later than forwards and midfielders but earlier than goalkeepers. This can be explained by the physical demands of each position. Consequently, we assume that defenders peak at 27.
How much do players usually improve from 20 to 27?
This is where player evaluation models would come into play as offered by 21st club, Goalimpact or many other companies. At the simplest level, ratings from Football Manager can also be used.
Let’s define the average rating of an average centre-back at 20 with Y and at 27 with Z. Now, we can calculate the percentage of how much centre-backs usually improve from 20 to 27 by dividing Z (Rating at 27) by Y (Rating at 20) and subtracting 1. b represents the percentage the player will increase on average.((Z/Y) -1) = b
Let’s say the result is b = 30%. We can then assume that the average centre-back aged 20 improves his rating by 30% until he reaches his peak.
This number serves as our base rate / outside view.
Inside View
Having evaluated the outside view, we can now zoom in into De Ligt’s particular case and evaluate its uniqueness to adjust our forecast. It’s important to note that there is no one pathway to a “yes” or “no” answer to the hypothesis that De Ligt will improve by 30%. In contrast, there is much information that must be weighted, against each other.
1. What information do we have that makes us optimistic that De Ligt will improve by 30% or even more?
He plays in a weaker league compared to Serie A. We assume that competing with better players in training and better teams, week in and week out, might help to raise his level. +5 percentage points (p.p.)
He only missed 5 matches due to injuries in almost 3 years as a professional. Therefore, we assume that he will be spared from injuries for the most part. +5 p.p.
Besides, more elements could be researched and might give us a better sense of how likely De Ligt will improve by 30%. Exemplary elements:
We have an organizational culture that allows (young) players to flourish and get the most out of their potential
We have a head coach, who has a track record of integrating, further developing, and generally improving (young) players
However, for now, we assume that none of them applies to Juventus.
2. What information do we have indicating that he might not improve by 30%?
There are many signs of early maturity -10 p.p.
He looks and behaves like an adult
He was captain from March 2018 until his transfer
He has an impressive and very mature physical presence for his age
He already has an impressive experience
He made his debut aged 17,1 in September 2016 and has (at the latest) been a regular starter since August 2017
He has international experience: national team, CL, Europe League final, etc. (youngest player to start for the Dutch national team since 1931; youngest player ever in a Major European Final, etc.)
There are signs that top players peak earlier -15 p.p.
According to the article from 21st club, only 54% of the top 50 aged 21 or younger at the end of 2012/13 improved at all
His playing style is already at or close to a world-class level
There are other, similar questions worth evaluating, e.g.: -4 p.p.
Do young players from the Netherlands or a particular style (= Ajax) disproportionally grow or decrease in value/rating after purchase? Especially when clubs have such outstanding seasons as Ajax in 2018/19, where everything seems to fit together, we should ask:
How much of the stars’ success is skill or because of the organization they play in?
How much of the skill is really unique to the star and therefore portable?As Michael Mauboussin explains in his book The Success Equation, organizations (regardless of their industry) tend to overestimate to which degree the abilities are transferable.
Having evaluated the outside and inside view, we can now merge and contrast the two. We would conclude that De Ligt will improve his current rating by 11% until he reaches his peak. Given his current rating of 77, his peak is between 85 and 86.
Another element worth noting is the influence of luck. It is hard to define where exactly talent development may lay on the luck/skill continuum by Michael Mauboussin. However, it certainly plays an important role as already indicated in 21st club's article, and as further strengthened by numerous top talents who were already praised The next big thing but never made the leap.
What we also do know is that the margins are very small at the top end of the player cluster. The level is simply so high and competitive that little details can have a great influence. Therefore, we should keep in mind that De Ligt’s development is not only a question of skill but also luck.
What certainly helps to reduce the influence of luck is a clear concept of how to integrate new players into the team and provide them with an organizational culture, in which they feel comfortable to reach their potential. A recent study by McKinsey analyzed how the 69 most valuable European clubs created (monetary) value over the past five years. The authors found that 2/3 of value increase can be linked to team value management, which essentially refers to the concept of managing an existing squad. Even though this study has its limitations, it highlights the importance of how a club manages the players and allows them to flourish.
Regardless of the forecast, there are other elements, a club might want to consider in favor of his purchase. For one, Juventus would not only acquire a high-rated player but, potentially, also a future captain. Besides, and arguably the most crucial argument is the fact that De Ligt could become their centre-back for the next 10-15 years. Dedir (2016) and Kalen et al. (2019) found that centre-backs age more slowly than strikers and midfielders due to the physical demands of each position. In fact, they don’t decline drastically until the age of 31 or 32. While they lose athleticism, they usually acquire other skills to balance this loss out, e.g., smarter decision-making.
Source: Dendir (2016)
Conclusion
It’s important to note that this is a very simple approach to get a feeling and a first rough estimate of a player's development based on many assumptions. As this was a calculation in hindsight, we can already conclude that De Ligt picked up injuries in his first 1.5 years at Juve, which slowed down his development. Initially, given his previous history of injuries, one could assume that he will be spared from injuries for the most part. This, however, is a perfect example of how wrong one can be wrong in assumptions. Besides, Juve had to deal with internal disagreements, which led, among other things, to a change of their head coach.