Tracking data changed tactics before it changed training

Optical and wearable tracking gave coaches a continuous picture of where players are and how fast they got there. Tactics adapted quickly; physiology did not.

What the data settled

Pressing structures, defensive lines and substitution timing are now argued with positional evidence rather than intuition. That part worked.

What it did not

Load management still rests on small samples and contested models. Knowing a player ran further does not tell you whether they were closer to injury.