Qui-Gon Jinn's Lightsaber Skills
I think that Qui-Gon Jinn is quite underrated, not so much when people discuss him against fellow Jedi, but especially his two duels against Maul. In both instances Maul struggled (if that's the appropriate word) against the Jedi Master, and was without doubt a match for Maul.
Jinn was generally regarded as one of the best pure swordsmen the Order had ever seen.
His technique as a pure swordsman made Jinn one of the best the Order had ever seen. This is not a surprise considering his master was Dooku, and Dooku's master was Yoda himself. This is made more impressive in that Jinn was a master of Form IV only, and yet is still placed up there with swordsmen who had mastered multiple if not all forms of lightsaber combat, such as Drallig, Windu and Anoon Bondara.
Anoon Bondara was advanced enough in lightsaber combat to be named Jedi Battle Master. I will use this quote from Wookiepedia but please note this isn't a good source of information, but this passage explains the history of the temple's battle masters:
In both of Bondara's appearances he is described as having lightsaber skills second to none. This has led some to hypothesize that Anoon Bondara was the Jedi Battlemaster prior to Cin Drallig. The information mentioned above, the fact that he was the lightsaber instructor to Jedi Initiates and Padawans such as Obi-Wan Kenobi, and that he died in 32 BBY, the same year Cin Drallig became Battlemaster, are cited by some to support this theory.
From this, it's most likely the Bondara was the battlemaster before Drallig. This places Bondara and Drallig as roughly equals, and implies Bondara to be a master of all seven lightsaber forms, as a battlemaster and instructor would need to be, as Drallig was.
Considering the skillset we have formed for Anoon Bondara, consider this:
Renowned for his skill with the lightsaber, Jedi Master Anoon Bondara is regarded by many of his peers and all of his apprentices as a role model whose combat prowess is unmatched in the Jedi Order. Bondara would disagree with this assesment. During his tenure at the Jedi Temple on Coruscant, he spars with superior lightsaber duelists such as Qui-Gon Jinn and Mace Windu. Although he humbles himself when compared to their skill, Bondara's prowess is nontheless considerable.
Despite Bondara being the battlemaster of the temple as well as implied to be master of the seven forms; Jinn (and Mace) were superior duelists to him. This shows that Jinn's application of Form IV was that advanced. This places Jinn above Drallig as well, assuming Bondara and Drallig are roughly equals.
A Twi'lek, with slender head-tails and a heavily muscled upper body, his name was Anoon Bondara, a duelist of unparalleled skill. Qui-Gon engaged him in matches at every opportunity. For a match with Bondara, no matter how brief, was more instructive than twenty contests against lesser opponents.
This implies that Jinn could outspar Bondara briefly in some cases as well.
Bondara's form of choice was Form VII Juyo. This explains one of the reasons why Jinn was so comfortable matching Maul; because Jinn had outdueled battlemasters who's go-to form was Form VII, which was Maul's preferred form.
The fact that Jinn can match Form VII with Form IV can be explained by experience facing it (he engaged Bondara in sparring marches whenever he had the opportunity) as well as influence from Dooku. By this, I mean that Jinn used some elements of Form II in his own technique. We find evidence in this when he fights two combatants and shunts each one aside in order to fight them one at a time, a very Dooku-eque technique. Though I doubt he integrated that much of Form II, at most the addition of feints and shunts to supplement the inherent defensive weaknesses of Form IV. This opinion however is highly speculative.
He also supplemented his Form IV with other fighting techniques as well:
Qui-Gon Jinn's lightsaber may not be as ornate as that of his mentor, Count Dooku, but true to his rebellious ways, he used it to master the same classical fighting techniques as well as untraditional combat forms from across the galaxy.
Assuming 'classical fighting techniques' further corroborates that Jinn mastered Form II techniques from his mentor/master Count Dooku as well as untraditional combat forms.
So this places Jinn above Drallig and Bondara, and he (as I will soon explain how) could match Darth Maul as a lightsaber duelist. Maul is a definitive 8, which would also make Jinn an 8. This also makes sense since Mace is also an 8, and they are both listed as superior swordsmen to Bondara.
Now I will address his two duels with Maul.
Regardless, Qui-Gon had quieted his mind and brought his imposing might to bear against Maul’s agility. He had matched Maul’s furious strokes with a disciplined intensity all his own. In the midst of their no-quarter contest the Jedi had even managed to order the slave boy to flee for the safety of the waiting ship, where Maul had nearly forgotten all about him.
The Force favors this Jedi! Maul recalled thinking.
After all the droids, assassins, gangsters, and soldiers he had vanquished, finally a worthy opponent. Not since he had fought and been defeated by his own Master, Darth Sidious, had Maul been so committed to a challenge.
Here it says that Jinn matched Maul blow to blow. It also displays Jinn's experience in high intensity lightsaber duels, since Jinn remembered Anakin, yet Maul did not.
Obviously, the fact that Jinn was his first worthy opponent (not considering Sidious who is leagues above both) other than gangsters etc. is not surprising, however, Maul was committed to the challenge, which means Jinn matched him.
But he is graceful, this Jedi. The sand doesn't see to hamper him. He is never off balance, no matter where or how I strike.
Despite Jinn facing Maul's Form VII offensive, he did not become unbalanced in the sand, despite every attempt by Maul.
The Jedi meets my first blow, blocking it. He has expected my flying maneuver.
If an opponent can read you, the fight is over. I don't like that the Jedi was perfectly prepared for my first blow. Within seconds, I throw away my usual combinations and strategies. This Jedi seems to know how I will move before I do.
Jinn is so advanced a duelist that he can see what Darth Maul (a solid 8) is going to do before it happens. He even goes as far as to say that the fight was over. However he didn't anticipate Jinn's flagging stamina.
Qui-Gon’s shrewd readiness had almost taken Maul off his guard.
Another example to show how Jinn matched Maul as a lightsaber duelist.
At this point I will point out that in the novelisation, in Jinn's perspective, Maul was:
younger, quicker and stronger than Qui-Gon,
And
The Jedi Master blocked him again and again, but could not find an opening that would give him any chance of escape.
So really, it was mostly experience that let Qui-Gon match Darth Maul blow for blow by knowing what Maul was going to do, despite Form VII being a highly randomised form that used unconnected sequences to confuse adversaries. This feat by Jinn can be attributed to his experience facing Form VII (Bondara) as well as his strength in the force. What makes this even more impressive however, is that every Form VII application is quite different, since the user draws from the styles they learnt.
"There," the Jedi breathed, pointing. They could see Qui-Gon Jinn now, engaged in battle with the dark-garbed, demonic figure. The combatants surged back and forth across the flats, lightsabers flashing brightly with each blow struck, sand and grit swirling in all directions.
This shows that the battle was 'back and forth' and definitely not a one-sided engagement. The open nature of the field of battle would definitely help Jinn due to his reliance on Form IV. This also means Jinn put Maul on the defensive half the time as well.
He had matched Maul’s furious strokes with a disciplined intensity all his own.
Again, here we can prove that Jinn matched Maul.
Then, just when Qui-Gon’s stamina was beginning to flag and the fight was tipping in Maul’s favor, the incomprehensible had occurred: Qui-Gon had fled.
I will note that Darth Maul is slightly better than Jinn, but only due to the Jedi Master's age and reduced stamina. But this only came into effect in both battles during the end stage.
But the horned attacker was already in pursuit, racing out pf the haze and leaping onto the ramp as the ship began to rise. Balanced precariously against the sway of the ship, eyes flaring in rage, he fought to keep his footing.
Qui-Gon attacked at once, rushing the other mam closing with him at the edge of the ramp... The Jedi Master and his adversary filled the viewscreen commanding the rampway entrance, faces tight with determination and streaked with sweat.
...On the screen, Anakin watched Qui-Gon Jinn step back, level his lightsaber, and swing a powerful, two-handed blow at his attacker. The horned man blocked it, but only barely, and in the process lost his balance completely. The blow's force swept him away...
This is more impressive for Darth Maul than Jinn, but regardless, Jinn immediately followed up on Maul's attempt to enter the ship, and Jinn was able to overpower Maul, though granted Maul was on the lower end of the ramp.