why compression doesn't perfectly even out entropy

[JonWienke at aol.com]

>Is it possible to find a percentage of the key space to eliminate that
>will optimize security assuming that the attacker will try the easy
>stuff first (and is it possible to quantify "easy stuff")?

If you eliminate all repeating byte sequences, such as 00 00 or 7F 7F, you
will reduce your possible entropy by .07058% (7.99435 bits per byte), and
eliminate the (astronomically remote) possibility of Hamlet or some other
English text popping out of your RNG/PRNG.  As long as your key is long
enough to withstand this slight entropy reduction, you are still OK.