Skild AI says it trained a robot to play football by letting it play against itself for 140 years inside a simulation. ⚽️ The clip is labeled autonomous, 1x. No pilot, no speed-up. Two things are doing the work here. First, time compression which is thousands of robot instances running in parallel physics sims, so what would be a century & a half of practice takes days of wall-clock training. Skild builds these on NVIDIA's Isaac Lab & Omniverse & describes gaining millennia of experience in days. Second is self-play. Nobody scripted a dribble or a shot. The system plays opponents that are copies of itself, & because the opponent improves whenever it does, the difficulty curve is generated automatically - never so easy the policy gets lazy, never so hard it learns nothing. It's the same mechanism that produced superhuman Go. The hard part is the last step. A policy trained in simulated physics usually falls apart in a real body, where friction, motor lag & a slightly wrong mass estimate break everything. Getting it to transfer is the actual result & Skild has shown related generalization before with its models recovering from a stuck wheel in seconds, or walking with a broken leg after a few attempts. DeepMind did knee-height soccer robots this way in 2024. This is the full-size version.