I thought I should write my very first blog as if I had written thousands already. There is no reason for a commemorative beginning. With that in mind, this is a blog in answer to a question lifted by SithSkywalker8 in his blog at http://blogs.starwars.com/countofserreno/

The Yoda VS. Sidious fight has not to do with lightsaber skill....

I agree completely. However, offer a broader reason than he does:

ABOUT THE SITH PREPARATION
I have a few points to make from my extensive knowledge of the expanded Universe, all I can say about this situation is that the Sith spent 1000 years preparing in secret for the exact moment where Darth Sidious rises to power. One thousand years spent in secrecy to reach the destruction of all Jedi through the most powerful master and apprentice possible. One thousand years spent in preparation to come up with a perfect plan of seduction, luring, intrigue, betrayal. The Jedi had no chance as it were because both Sidious and Vader were part of a millennium of preparation. The Jedi had no chance because instead of preparing for the this future they spent 1000 years preparing for another Sith War like it was said already.

ABOUT THE DIFFERENCES BETWEEN ROTS AND OTHER SITH VS. JEDI EVENTS:
The Sith War was fought by thousands of Jedi against thousands of Sith. This event was only two most powerful users of the force and the jedi. The Jedi had no chance because the conflict was completely different. The Dark Power was fully concentrated and channeled in unison to ONE purpose: The destruction of the Jedi. It was never so before. It can be argued that Exar Kun worked separate from Ulic. The Sith War's Siths were simply too many. Sidious and Vader in the other hand had all the politic power, the element of surprise (that caught every single Jedi except for Yoda), and most important, complete control of the Force which the Jedi depended on. Jedi were fighting blind and crippled.

ABOUT TRAINING:
Someone argued Jedi could not have been trained differently. That is not true. Yoda himself fled not just because he realized he could not win due to the Dark Lords complete control of the force at that point, just as it was said before. Even if he could not win, he would have fought to the end and tried. "Try you will not. Do it or do it not." That is Yoda's philosophy. Yoda fled because he had an idea. He realized they should have been trained different indeed and that if he died, his idea would die with him. That is why Yoda fled. It had less to do with power and skill than with wisdom. Yoda fled because only he at that point knew what to do.

ABOUT MACE, ANAKIN, AND SIDEOUS
As to the confrontation between Mace and Sideous and Anakin goes... Sideous knew Anakin was coming. Mace beat Sideous only because he mastered a fighting style that was superior to all others and that "USED THE DARK SIDE" by definition so that he could channel the power of Sideous in his favor. Nevertheless, Sideous did not care; in fact, he knew that would happen and that it would provide the perfect situation for Anakin's fall. It was all planed, even his defeat. It is not that he let Mace win. It is more that he knew Mace would and that Anakin would be there in the right moment to rise as Vader.

Now the most important point:

WHAT DID YODA KNOW THAT MADE HIM LEAVE?
He knew, like it has been said, that one lone candle is enough to falter the dark. He was this candle. However, he did not have enough light to defeat darkness. He needed to keep his light on enough to wait for the moment where the right light would destroy the Sith: ANAKIN SKYWALKER was the only one who could destroy the Sith. His revelation was that the only way to destroy those who controlled the force was that the destruction was to come from within. Yoda never meant for Luke to defeat Sideous or Vader. If he could not, why would Luke? Too old, too impatient, too much of everything wrong? Nevertheless, Luke had something he could never have. LOVE. He had this bond with Vader that would be enough to ignite Stars! Even dead stars like the one in Anakin's heart (from the Novel as well). Luke's love (or that of Leia's had Luke failed) was the last hope for the Galaxy. The Jedi were trained wrong because they were trained to avoid loving. It is because of Love, arguably that Obi-Wan became what he did by the end of ROTS. IT was because of Love that Luke ignited something in Vader. Love brought Vader back from the Dark to the light. Then Vader from inside, destroyed the Sith. By the way, in the entire old trilogy, Luke is being manipulated by Yoda and Obi-Wan. They too had time to prepare. They are not training him to defeat Vader but to seduce him, literally, to love. The reason why Luke was not ready to confront Vader on ESB is that it would not be the appropriate situation for Luke to seduce Vader. The Emperor was not even there! Yoda knew then Luke would fail. He could never beat the Dark Side. Only Vader could. Even if he had beaten Vader (which would not have happened then) he could not destroy Sideous alone. The Emperor would win. In ROTJ they encouraged him to destroy Vader, otherwise the Emperor would win. Why? Because now it was the appropriate moment and they needed to put Luke in a situation where his demise would make Vader's love rise to destroy the Sith.

YES YODA WAS WISE!!
To put it simply. Yoda was even wiser than he was skilled or powerful. In the midst of the dark he saw the light for long enough to realize there was only one thing he needed to do. Flee and create a plan to destroy the Sith from within. The Force provided him with just that, through Amidala's love.

LOVE was the answer in the star wars universe. An answer that the Jedi did not have. They needed a new bread of Jedi. They needed Luke to bring Anakin back