This may help understanding cam advance and intake centerline.

When the rod and the crank throw are perpendicular, this is the point of maximum piston acceleration.

Some would argue this is also the point of maximum draw/pull on the intake mixture, although this point
is not quite an exact mathematical relationshp, but it's probably not too far off.

For most engines, the crank throw and the rod are perpendicular at approx 70 degrees ATDC to around 76 degrees ATDC,
depending on rod length and total stroke of course. 70 degrees in a "short rod" motor, 76 degrees in a "long rod" motor.

This is A LOT earlier than 100 degrees ATDC, which is considered pretty advanced for intake valve centerline.
The hidden question is: Should the intake valve be at max lift at the point of max piston acceleration for max breathing ?

Because of this, it should not be surprising that advancing the cam, i.e., the intake centerline, generally shows
up as higher torque output of the engine (in a given RPM range). It also shows how much of a compromise cam design
really is, they are not AT ALL ideal, but, it's the best we've got.

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Edit: Replace the phrase "piston acceleration" with "piston velocity". The degree numbers are correct, everything else
is correct. I can't believe I made that mistake.