I had one rooster with a single black spot, and the other two spotted ones were hens. The solid white ones were all males.Glancing through the thread - did it seem most pullets were the ones with a few black spots and the solid whites were mostly roosters? Had a few TJ eggs hatch out and it does seem like the solid white ones already have bigger combs.
n ratio. Often they'll use different colored roos to make that task easy. Don't know if TJ's does that, but it would make sense that, therefore, the white w/spots chicks could be Austra Whites, an Australorp x Leghorn cross.