To add to my last blog...
Dooku would have lost the fight to Yoda if not for his leverage of wounded Jedi....
Remember in Empire when Yoda is pleading for Luke not to go to Cloud City, he tells Luke that if he goes, he might save them, but he will have sacrificed all that they have fought for.
Perhaps this is Yoda speaking from experience....
Save them(Anakin and Obi-Wan), he did, but he allowed to Dooku to escape, thus giving Dooku the opportunity to lead the Seperatists into a great Civil War. If Yoda had taken his own advice to Luke, perhaps things would have been different. Perhaps allowing Obi-Wan and Anakin's sacrifice, he would have defeated Dooku and stopped the Clone Wars. Who knows what would have take place then. There would be no Vader. There would be no Luke and Leia. The galaxy sure would have been a different place...
I'm not saying it would have been the right thing to do (as Luke ultimately proved again, by saving Han and Leia, they eventually did overthrow the Empire), but maybe this is what Yoda was referring to.
Your thoughts are always highly welcome!

God bless