The Process Bob posted was an early version, and was a flow chart. One step in the flow chart was "Review and discuss if it makes sense, and return to areas where it doesn't", or something similar.

So, in pracice, we saw that those starting points were making little sense, and we used the 'return" function to get closer to reality, and 25% became SOP in most cases. As a matter of fact, we discussed 30 or 35% as a POS factor. POS stood for, well, you know. Basically old emission era cars that, when you remove air pumps, horrible exhaust manifolds, and carb issues, they REALLY wake up.

Further, and this was a bit before my time, but the 142 was used as a bogey.

IMO, the G3# is 50 light because I think it got a rear axle break, which I don't think should be used.