Obi-Wan Could Have Beaten Vader in A New Hope - If He Wanted To. While
It's actually quite simple, really: He let go of self and allowed the Force to work ITS will, not his own, through him.
He couldn't bring himself to kill Darth Vader, however, because he continues to associate him with the Anakin he trained as a boy. This is also the exact reason why Obi-Wan didn't kill Anakin on Mustafar despite the opportunity a decade earlier in Star Wars: Episode III - Revenge of the Sith.
In Star Wars Legends and Canon, Galen Marek (Starkiller) is the only Jedi (other than Obi-Wan Kenobi) to put a beat down on Darth Vader/Anakin Skywalker.
In addition to getting older, Obi-Wan's life as a whole has slowed down considerably. He hasn't been using the Force, nor has he been training padawans or saving the galaxy from the Sith. With these things in mind, it makes sense for Obi-Wan to be rather weak in his new Star Wars show.
The reasoning comes from, not only his fears that he isn't strong enough to defeat Vader after 10 years in hiding but the fact that facing Vader means Obi-Wan will have to face up to his greatest failure.
Throughout her encounters with Kenobi in the series, he refers to himself as Ben. The most straightforward explanation would be that Leia knows the person who rescued her is Ben, and never connected the dots that Ben is actually Obi-Wan.
1. Obi-Wan Kenobi. Of all today's characters, Anakin's own Jedi Master most notably conquered the newly-fallen Sith Lord at the height of his power, before his need for movement-restricting armor.
Some time later, he faced the Sith Lord Darth Vader. Infil'a put up a fierce fight against Vader, almost killing him by throwing the already damaged Sith Lord off of a cliff. Despite severe damage to his suit, Vader survived the fall, and repaired himself with parts from Infil'a's droid, Arex.
Vader, the only power who overrules him is papa Palpatine. The reason why Vader obeyed tarkin was out of a sense of respect for him as a military leader, not as his superior.
Yes he did. And the saddest thing is that there was nothing he could do about it. He was broken. The first case is shortly after ROTS when Vader was making his Sith lightsaber.
Obi-Wan knew it was only a matter of time. So, he made the difficult decision to use his learnings and become one with the force, rather than let Vader decapitate him.
5 Losing Obi-Wan
While there may be several Jedi Masters that were better for Anakin, there's no denying that the bond between Obi-Wan and Anakin is strong. Unfortunately, this makes Anakin's fear of losing him strong as well.
He slays Sidious and returns to Obi-Wan, begging for atonement by execution, only to be met with true forgiveness instead. But just as this fantasy Obi-Wan refuses to strike his former friend down, Vader refuses to turn his back on the dark.
Powers and Abilities
The Force: Kenobi was extremely powerful, and had an extremely strong connection to the Force, and was one of the most powerful force users of his time. Though Kenobi did focus largely on Lightsaber combat, he was also very skilled and powerful in use of the Force.
Is Obi-Wan Kenobi More Powerful than Darth Vader? There just isn't any way that in an even fight Obi-Wan beats Vader. Although Vader is supposed to be one of the strongest force users of all time, we actually haven't had a chance to see him using his full strength very often.
At that moment, the one in which Vader screamed, "No!" in Revenge of the Sith, the Sith apprentice believed himself to be his own worst enemy. Vader hated himself. It likely only grew worse when Vader realized that Palpatine had absolutely played him.
Ahsoka Had the Highest Kill Count of the Clone Wars
Ahsoka is known for being one of the more pacifistic Jedi, to the point where she refused to kill any Clones during Order 66. But when it comes to destroying battle droids, Ahsoka is far in the lead with a staggering 4 million kills throughout The Clone Wars.
Darth Vader is one of the best villains of all time, and across his years, he has killed some very important Jedi in the Star Wars series. Across the galaxy far, far away, one terrifying Sith Lord has been wiping out remnants of the Jedi Order for years.
Aside from agility and telekinesis, Yoda could absorb and redirect Force attacks, like lightning. Because of his higher understanding, he would easily overcome Darth Vader in a fight, though that doesn't mean it wouldn't be a difficult battle.
Darth Vader defeats Darth Maul. The two Sith Lords engaged in a lightsaber duel, going through the volcano and onto a bridge situated over a river of lava, which collapsed, though they both survived and continued their battle.
Many fans declare that Luke won the confrontation because he nearly killed Vader, but that's technically not true. Vader was far more powerful than Luke and easily could have bested him.
Obi-Wan greets R2-D2 and later recalls “not owning a droid.” Obi-Wan purposely withheld information from Luke in order to keep Luke from straying away. This could offer an explanation as to why he appears to not know who R2-D2 is. Further in Empire Strikes Back, neither Yoda nor Darth Vader recognizes either droid.
Yes he did. And the saddest thing is that there was nothing he could do about it. He was broken. The first case is shortly after ROTS when Vader was making his Sith lightsaber.
In the story, we learn that Obi-Wan took on the name Ben because it's a nickname given to him by an old flame, the Duchess Satine Kryze. He takes on the name because it still has emotional resonance for him.