The California halo is a school effect, not a teammate effect
A full rederivation, registered as research finding RI-RF408, puts the raw gap at 10.1 points on 4,698 California prospects: 73.2 percent, 1,360 of 1,858, against 63.1 percent, 1,793 of 2,840. Hold the high school itself constant and the difference is -0.08 points on the 2,431 players at the 159 schools that hold both kinds, an interval of -3.77 to +3.61. Only 12.4 percent of the 42,058 California players rostered in these classes carry any rating at all, and that narrow slice is where the earlier claim came from.
Recruit Intel rebuilt its own halo claim from raw data and registered it as research finding RI-RF408. The raw gap between California prospects with a blue-chip teammate and those without is 10.1 points, 73.2 percent, 1,360 of 1,858, against 63.1 percent, 1,793 of 2,840, on a cohort of 4,698 rated players in the classes of 2014 through 2024. That is about three times the 3.5 point figure a now retired Recruit Intel piece carried, and the retired number does not reproduce in either direction.
Hold the high school itself constant, comparing only players inside the 159 schools that produced both kinds, and the gap is -0.08 points on 2,431 players, an interval of -3.77 to +3.61. The halo is a property of the school, not of the teammate. Only 12.4 percent of the 42,058 California players rostered in these classes carry any rating at all, and sharing a school with a blue-chip makes a player more likely to sit inside that counted slice in the first place. The full ladder of controls, the coverage problem, the dissent recorded on the finding, and the correction to our own earlier claim are below.
