Darth Sidious- The Man, The Lost Twenty & His Apprentices
On the subject of The Lost Twenty & The Sith Order. Now, I allow my thoughts dwell on this piece as items I reference to are included the novelisations of TPM and AOTC.
Info #1: The Sith Order at one point initiated a rule of two- a master and an apprentice. This rule is something the Jedi exert as well, so it really helps to show that you really have these two sides to a Force. Using the light side, and following a rule of two seems to bring about an abundance of Jedi who can live in harmony. Those mis-using the Force obviously cannot survive in large numbers, but they can maintain a balance (ie, their meager survival) through a rule of two.
Info #2: Over the course of time, the Jedi have had 20 members of thier order leave. To where, we are never told. But I have a theory:
As to whether higher Jedi know, or not, I can't tell. But lets combine a few pieces of information. Mis-use of the Force can obviously lead to quite some power- perhaps the ability to cheat death. If so, a Sith Master could live for quite while, yes? A Sith Master must have a Sith apprentice, So he must train someone. Perhaps each of the order that have left have become the apprentice to the same Master. Over hundreds of years.
Sidious could very well be a master in equal age to Yoda. The same Master, prolonging their life through the Dark Side could live forever. We've seen in the movies that Sith apprentices seem to be throw-away. Perhaps Sidious really does go through them one after the other, besides, with his power they would never be a real threat. The only set-back is to have to waste another 20 years training up a new apprentice. Perhaps, when Sidious cannot find a child with a high midichlorian count in the Outer Rim, the quicker solution is to seduce a Jedi with power.
Sidious could very well be the instigator of this current 1000 year old plan of the Sith to grab at power.
But imagine when someone as powerful as Anakin comes along. Here is a Jedi that should surely be Sidious's apprentice. With someone of Anakin's power under his control, Sidious would indeed be able to wipe out every last Jedi. But perhaps Sidious sees that Anakin could also be his biggest threat.
I wouldn't be surprised if Sidious knows Anakin's fiery fate, and is thankful for it (as it would potentially reduce Anakin's potential).
Just some things to chew on.