In short, the Mace vs Sidious duel and Dooku vs Anakin duel are each very ambigious and hard to detail. It leaves many questions open.
Yoda did NOT defeat Sidious in his battle with the Sith Lord in the Senate chamber. The site says that Sidious was too powerful for Yoda to defeat, though Yoda held his own for much of the fight.
But everyone believes Mace did defeat Sidious with Sidious going all out. If that's true, then are we to believe Mace is superior to Yoda? Or did the circumstances favor Mace? Or did Sidious simply not think of Mace as a legitimate threat? Or was it all simply orchestrated by Sidious to turn Anakin?
There are strong implications of the final two possibilities. Sidious did NOT use the Force in the same mannerism that Dooku did not use the Force against Anakin. Only against Obi-Wan. Sidious didn't use the Force against ANY of his Jedi Master foes.
So. Sidious might have not registered Mace as a threat, having killed three of his Jedi compatriots in less than ten seconds. So that may explain why he did not use the Force against him.
However. Sidious DID attempt to when Mace had him on the ground. This attack obviously did not work. So this also leaves questions open for consistancy.
In my belief, Sidious did a combination of acting overconfidant and then manipulating Anakin.
Sidious killed three of the four Jedi Masters with ease. He engaged in a saber fight with Mace for a little while, sparring. No where near exerting the intensity that he did with Yoda.
Then, when Mace outmaneuvered him and kicked his weapon away (that doesn't mean, by the way, that Mace is the better duelist) did Anakin arrive. Perhaps it was purely by coincidence.
But coincidence RARELY happens in Star Wars. Especially involving Sidious.
Now. Sidious had no saber. So here he was screwed, to put it lightly. This is where the situation either escaped his control, or where it was actually in his grasp still. Here, he cunningly manipulates Anakin into a test of loyalty. What better way to forever close off the Jedi to him, by participating in the death of one of his masters?
Anakin wasn't going to KILL Mace. That became evident when he agreed Sidious ought to have a trial. He didn't want to kill Mace or then see Sidious go unpunished. But he NEEDED Sidious alive. If Anakin was looking to kill Mace, he would've pierced his heart instead of disarming him.
Sidious must've realized this, and took the liberty of killing Mace all on his own.
Another inconsistancy is that in the book, Vaapad is the source of Palpatine's disfiguration. That the bolts channeled back from the saber onto him. True, sparks did fly across his face, but I don't recall it coming from the saber. It might have.
The Star Wars site declares that Sidious "became a well of Dark Side energies" proving that Sidious was so powerful in the dark side that it prematurely aged him as well as extended his life. He and Yoda are VERY similar, there.
Yoda and Sidious act in the same manner. They pretend to be weak and feeble when in truth, they are amazingly powerful. Like Sidious, when Yoda did NOT use the Force, he was fatigued and winded. Like an old man.
Odd how similar they truly are.