Calibration
VideoMMMU → CharXiv
CharXiv is estimated from VideoMMMU with a Hill curve fitted on 10 models measured on both: y = 0.0000 + (1.2000 − 0.0000)·x^6.00 / (0.75823^6.00 + x^6.00), R² = 0.35, cross-validated error 5.9 pp. It is used for 0 estimates.