Compression Ratio - Why is it too much?

[spetz]

Is there a magical number where say 1 point is X % more power?

[iamhappy46]

Hypothetically, if the engine has 10:1CR stock and you raise it to 11:1CR, it theoretically should yield a 10% increase in torque.
As: HP = Torque x RPM / 5252, a 10% increase in torque is available across the entire rev range and therefore, a 10% increase in power across the rev range.
Such that, 12:1CR should yield a 20% increase in torque and therefore power.