Two families with identical scores don't have identical chances
En Girona, un padre analista de datos ha convertido una inquietud personal en un acto de transparencia colectiva: al descubrir que más de 350 familias empatadas en puntuación no tenían las mismas probabilidades reales en el sorteo de plazas de guardería municipal, construyó una herramienta que hace visible lo que el sistema nunca había explicado. La historia no es solo la de un padre ingenioso, sino la de cómo la opacidad de los mecanismos públicos puede perpetuar desigualdades silenciosas incluso cuando las reglas parecen iguales para todos.
- Más de 350 familias en Girona descubren que empatar a 30 puntos no significa competir en igualdad de condiciones: el sorteo del 2 de junio esconde asimetrías de hasta 40 puntos porcentuales entre candidatos idénticos.
- Roger Sanjaume, analista de datos y padre afectado, detecta que el mecanismo del sorteo trata de forma desigual a quienes el sistema considera matemáticamente equivalentes.
- En respuesta, construye una aplicación web que permite a cualquier familia calcular su probabilidad real antes del sorteo, usando únicamente datos públicos que nadie había cruzado de esta manera.
- La herramienta no impugna el sorteo ni lo detiene, pero expone con precisión lo que estaba oculto: que la aleatoriedad del sistema no era tan aleatoria ni tan justa como se asumía.
- La presión sobre las autoridades educativas de Girona y la Generalitat para revisar el mecanismo de adjudicación crece ahora que cientos de familias pueden ver su posición real en la distribución.
Roger Sanjaume, analista de datos, empezó con una pregunta personal: ¿cuáles eran realmente las posibilidades de su hija de entrar en una guardería municipal de Girona? Como más de 350 familias, había obtenido exactamente 30 puntos en el baremo de admisión, el umbral que enviaba todos los casos a un sorteo programado para el 2 de junio. Pero al examinar cómo funcionaba ese sorteo, Sanjaume encontró algo que no cuadraba: las probabilidades no eran iguales para todos.
Lo que comenzó como curiosidad se convirtió en una pequeña herramienta de transparencia. Sanjaume desarrolló una aplicación web que permite a cualquier familia en su misma situación introducir sus datos y conocer, antes del sorteo, cuál es su probabilidad real de obtener plaza en su escuela preferida. El sistema se alimenta de datos públicos —las listas de puntuación y el propio mecanismo del sorteo— para calcular algo que nunca se había hecho explícito: que familias con idéntica puntuación no tienen idénticas oportunidades.
Las diferencias son sustanciales. Según la posición de cada familia dentro de la estructura del sorteo, las probabilidades pueden variar entre 30 y 40 puntos porcentuales. Dos familias con los mismos 30 puntos, optando a la misma escuela, no parten del mismo lugar. No es un margen estadístico menor: es la diferencia entre una oportunidad razonable y una posibilidad remota, integrada en el propio diseño del sistema.
La aplicación no altera el sorteo ni cuestiona su legalidad. Simplemente hace visible lo que siempre estuvo ahí. Algunas familias encontrarán alivio en los números; otras sentirán con más fuerza el peso de esa brecha. El sorteo del 2 de junio se celebrará según lo previsto, pero la pregunta sobre si el sistema de adjudicación de plazas escolares es verdaderamente equitativo ya ha sido formulada en voz alta, y es más difícil de ignorar ahora que cientos de familias pueden verla reflejada en sus propias probabilidades.
Roger Sanjaume, a data analyst by trade, sat down to understand why his daughter's chances of landing a spot at one of Girona's municipal preschools seemed so uncertain. She was one of more than 350 families in the city who had tied at exactly 30 points in the application scoring system—the threshold that meant everything would come down to a lottery drawing scheduled for June 2. But as Sanjaume looked at the mechanics of how that lottery would actually work, something caught his attention. The odds, he realized, were not equal for everyone.
What began as a personal curiosity became a small act of transparency. Sanjaume built a web application that lets any family in his situation plug in their information and see, before the lottery happens, what their actual probability is of getting their child into their first-choice school. The tool draws on publicly available data—the scoring lists and the lottery mechanism itself—to calculate something the system had never made explicit: that families with identical qualifications do not have identical chances.
The disparities are significant. Depending on where a family falls in the lottery structure, their odds can swing by as much as 30 to 40 percent. Two families with the same 30-point score, applying for the same school, facing the same draw, do not have the same shot. The variation is not a rounding error or a minor statistical artifact. It is the difference between a reasonable chance and a long shot, baked into the system itself.
Sanjaume's observation cuts to something deeper than a single school year in a single city. The lottery mechanism, as it exists, treats mathematically identical applicants as if they were not identical at all. The families who built their applications carefully, who met every criterion, who ended up tied with hundreds of others—they discover now that the tie-breaker is not truly random in the way they might have assumed. The system has hidden asymmetries.
The application Sanjaume created does not change the lottery or challenge its legitimacy. It simply makes visible what was always there. Families can now see their own position in the distribution, understand their actual odds, and make decisions with more complete information. Some may feel reassured. Others may feel the weight of those 30 or 40 percentage point gaps more acutely.
What happens next depends partly on whether the city and the regional education authority take notice. A tool like this, built by a parent with the skills to see what others might miss, has a way of raising questions that are harder to ignore once they are asked. If hundreds of families now know that the lottery is not as fair as it appeared, the pressure to examine and possibly redesign the mechanism may grow. The June 2 drawing will happen as planned. But the conversation about how schools are allocated, and whether the current system truly serves families equally, may have already shifted.
Notable Quotes
By a mathematical curiosity, not all families have the same opportunities at the moment of the lottery draw, and there can be variations of between 30% and 40%— Roger Sanjaume, data analyst
The Hearth Conversation Another angle on the story
Why did you decide to build this tool? You could have just accepted the lottery like everyone else.
I couldn't. Once I saw the math, I couldn't unsee it. My daughter was one of 350 families in the same situation, and I wanted to know if we really all had the same chance. The answer was no.
But the lottery mechanism is public information. Couldn't other families have figured this out themselves?
Technically, yes. But you need to be comfortable reading probability distributions and understanding how the lottery algorithm actually works. Most people don't have that background. I built the tool so families didn't have to be data analysts to know their odds.
Do you think this will change how Girona allocates school spots?
I hope it raises questions. If 350 families suddenly realize their odds vary by 40 percent even though they're all tied at 30 points, someone will have to explain why. That's when real change might start.
Aren't you worried about making families more anxious before the lottery?
I thought about that. But I think knowing the truth is better than living with false certainty. At least now families can make informed decisions about whether to appeal, whether to look at other schools, what to expect.
What would a truly fair lottery look like?
That's the question the city needs to answer. Maybe it's a simple random draw with no hidden asymmetries. Maybe it's a different allocation system altogether. But first, you have to see the problem.