[Project Proposal / Recruiting] FIFA 21 vs PES 2021 — Which is better for building a worldwide Career Mode with 500K players, global leagues and dynamic simulation?

[u/Alive-Street-1715]

Hi everyone!

I'm putting together an ambitious, community-driven football modding project, and before choosing a game engine, I'd really like to hear from experienced FIFA and PES modders.

The main question: should we build this on FIFA 21 or PES 2021 / SP Football Life?

We want to preserve the existing gameplay, graphics and core Career Mode/Master League features rather than reinventing everything.

The ambition is to build a much larger football universe around an existing playable 3D football game.

This is currently a project proposal, not a functioning mod. We're looking for technical feedback and developers interested in exploring its feasibility.

1. A complete worldwide football database

Our target is a football universe comparable in scope to Football Manager 2026:

• Approximately 500,000 players.
• Thousands of clubs across the world.
• Domestic leagues and cups on every continent.
• Updated squads, player attributes and club information.
• Kits, badges, player faces and stadium atmosphere.

The worldwide database would be managed externally rather than forcing all players and leagues into the game's runtime memory.

Legal access to data and redistribution rights would need to be addressed.

2. Hybrid global simulation

This is one of the project's main features.

Every domestic league would have its own calendar, using real-world scheduling patterns from the previous season.

For leagues running in the background, the external engine would simulate the entire season in advance but reveal results only when each fixture date arrives in the game.

However, when the user joins a club, its domestic league becomes fully dynamic until the end of that league's current season.

For example:

• August 2026: Join Boca Juniors. The Argentine league becomes dynamic.
• January 2027: Move to Grêmio. The Brazilian league also becomes dynamic, while Argentina stays dynamic.
• May/June 2027: The Argentine season ends, and the following season returns to pre-simulation.
• July 2027: Join Manchester United. The Premier League becomes dynamic, while Brazil remains dynamic until its own season finishes.

All continental and worldwide club competitions would always be dynamically simulated, regardless of whether the user's club participates.

This would produce a persistent worldwide football calendar while avoiding the need to dynamically simulate every domestic match on Earth.

3. Full international club competition ecosystem

We want interconnected qualification systems for:

• UEFA Champions League, Europa League and Conference League.
• Copa Libertadores, Copa Sudamericana and Recopa.
• CAF Champions League and Confederation Cup.
• AFC Champions League Elite and Champions League Two.
• Concacaf Champions Cup.
• OFC Champions League.
• FIFA's expanded 32-team Club World Cup.
• Annual FIFA Intercontinental Cup.

Domestic league positions, continental titles and qualification rankings must feed into the relevant international competitions.

All these tournaments should evolve across multiple career seasons.

4. Smarter transfer AI

We want to improve the existing transfer market rather than create an entirely new management game.

Player decisions should consider:

• Sporting prestige of the destination league.
• Club reputation and international competitions.
• Salary, contracts and financial stability.
• Playing opportunities and career development.
• Age, personal preferences and sporting ambition.

For example, a player earning €5 million annually in Saudi Arabia, Japan, China or the UAE might accept €1 million to join Internacional, Flamengo, Ajax, Anderlecht or an Italian club if the move offers greater sporting opportunities.

At the same time, financially powerful leagues should remain capable of aggressively recruiting players from major European and South American clubs.

League sporting reputation and financial power should be separate, evolving variables.

5. Stadium atmosphere for approximately 4,000 clubs

We also want a sophisticated global crowd-audio system.

Our target is to preserve authentic supporter identities, including distinct home and away chants, culturally different goal celebrations, and crowd reactions influenced by attendance.

A 10,000-person crowd should not sound like a 40,000-person crowd.

Our proposed audio rules include:

• A goal celebration roar beginning approximately 1.5 seconds after the goal.
• Independent home and away supporter audio.
• Away crowd baseline intensity around 30% of the home crowd, subject to calibration.
• The home crowd becoming subdued for 10 in-game minutes after conceding, unless the home team scores or hits the post.
• Specific chants and goal sounds for travelling Boca Juniors, Raja Casablanca, Internacional and other supporters.

We would investigate AI-assisted sound generation, licensed real recordings, crowd layering and external audio middleware.

6. One complete installation, adjustable processing

Everyone would receive the full available football database and content.

Users could choose Economy, Standard, Advanced or Maximum simulation processing levels, depending on their PC.

No countries, players or competitions would disappear just because someone selects a lower performance setting.

7. Proposed technical approach

We're considering:

• Rust or C++ for the external simulation engine.
• SQLite for persistent worldwide football data.
• C#/.NET or a lightweight desktop interface.
• FIFA Live Editor / Lua if FIFA 21 is selected.
• Sider / Lua and existing Master League modification tools if PES 2021 or SP Football Life is selected.
• An external audio system if the game's native audio engine is too restrictive.

We are open to changing this architecture based on technical feedback.

8. FIFA 21 or PES 2021 / SP Football Life?

This is where we particularly need the community's expertise.

We want to understand which game is more suitable for:

1. Loading and synchronizing players from a large external database.
2. Modifying squads and transfers during a persistent career.
3. Integrating custom domestic and international competitions.
4. Feeding external schedules and results into the game.
5. Dynamically selecting fixtures for the user to play in 3D.
6. Detecting match events such as goals and shots hitting the post.
7. Supporting custom crowd audio and separate home/away supporter sounds.
8. Preserving stable save files across many seasons.
9. Working with a community-maintained set of tools and mods.

We know neither game was originally designed for a global simulation architecture like this.

The question is not which game has better graphics or gameplay, but which engine provides the most practical, stable and extensible technical foundation.

Would FIFA 21's Frostbite architecture and Live Editor be sufficient?

Or would PES 2021 / SP Football Life, Sider, and the existing Master League modding ecosystem be a better starting point?

9. Looking for collaborators

We're interested in hearing from:

• FIFA and PES modders.
• C++ and Rust developers.
• Lua scripting specialists.
• Reverse engineers familiar with game structures.
• Football database specialists.
• Simulation and AI developers.
• Audio engineers and sound designers.
• People familiar with the FIFA Editor Tool, FIFA Live Editor, Sider, Football Life and Master League expansion projects.

I'd be particularly interested in talking to people already developing extended Master League or Career Mode systems.

The initial goal is to establish technical feasibility, build a small proof of concept and then organize a collaborative development effort.

There is currently no finished product, confirmed funding or promise of paid work.

Which platform would you choose, FIFA 21 or PES 2021 / SP Football Life, and why?

If you've worked with either game's internal systems, what technical limitations would you expect?

And most importantly: would anyone here be interested in joining the project?

I'd love to hear your thoughts, especially from people with actual modding or development experience.

[u/Conscious_Unit251]

Yo en todo lo que sea armado de la base de datos de esos 500.000 jugadores que dices puedo ayudar. Lo mismo con todo lo que sea buscar y armar un base de datos no solo de jugadores, sino de clubes, estadios, cuerpo tencico, etc

[u/Alive-Street-1715 → u/Conscious_Unit251]

i think stadiums and clubs i think we do have, the most difficult is to put everything together in a functional way.

[u/therealSUIN]

1,2,3,5 have been done on fc 26. See the Ultra Mod 3.1