Here’s a concise, full review of how the development data (player growth/potential) compares between and FIFA 19 , and which is "better" depending on what you value.
FIFA 19, benefiting from the Frostbite engine, utilizes a real-time physics solver. The code doesn't just say "Player A tackles Player B." It calculates the force of the impact, the angle of the studs, the flex of the knee ligament, and the weight distribution of both players.
: Mods like the Devdata DAT often come with community support, including forums, social media groups, or dedicated websites where users can report bugs, suggest features, and share tips.
In the FIFA 09 era, the game relied heavily on a simpler file structure. Much of the game's logic and database were contained within accessible archives. The devdata files (and similar configuration containers) were relatively easy to parse.