Introduction:

In Dragon-ball super anime, due to non-clear representation of power levels and some misunderstood statements, some people like to believe in "2-base theory" which is quite popular around many internet forums.

Here I will try my best to prove that this is nothing more than a misconception, and note that since this is specifically focused towards super anime, I won't use super manga for anything except providing some supplementary material and additional info for the anime which is treated as primary source material for the purpose of this thread.

Origin:

The "two base theory" or "god base theory" as many call it, originates from RoF movie where it was hinted that goku's base form probably rivals Super Saiyan god. However no explicit claim was made about that. Now, in DB Super, which essentially rewrote the movies, Goku said something like "I am the super saiyan with the power of Super Saiyan god" when he turns SSB. Hence many people assume that he had the power of SSG in base already. The fact that Akira Toriyama once claimed that Goku absorbed the power of SSG further supports this assumption.

However, when in U6 tournament, everyone is able to give base goku a hard time, people can't handle U6 characters being SSG level. So, there is now a theory that Goku can only use "SSG level power" in base when he uses his white aura.

The "theory":

According to this theory, sometimes, Goku uses a base which is on or above SSG lvl and sometimes he uses a base which is only slightly stronger than his BoG arc self.

To sum up:

Goku (Godly base) = SSG >>>>>> Super vegetto >>>>>>>> Fat buu >>>>> Namek Freeza 100% >= Goku (Ungodly base) > BoG Goku (base)

However, the major drawback in this theory is that it believes in this chain:

SSB > Godly base >>>> SS3 >> SS2 >> SS1 >> Base

The debunk:

Goku does not have god ki in base:

Everytime he has been in base, his base has been sensed. Krillin even remarked that his base is on an whole different lvl than his former self, in ROF. If he had god ki, krillin won't be able to sense him.

Goku's base is not SSG level:

So far, there is not a single explicit statement which puts goku's base on super saiyan god's level. Infact, there is plenty of evidence for the contrary.

1. Goku's fight against freeza

• King Kai's statement: "Amazing! Goku reached Super Saiyan god level again, and this time without the help of others."

If his base was anywhere near SSG level, then this statement entirely loses weight.

• Narrator: "In order to surpass the powered up Freeza, Goku mutated into a form that exceeded even Super Saiyan God."

The narrator statement makes it pretty clear that Super Saiyan god is a huge deal and only SSB can surpass it.

It also implies this:

SSB > SSG > Powered up freeza > Base goku

So SSG and base are not really in the same realm.

• Freeza (before goku turns ssb) tells goku to turn super saiyan and face him.
• Freeza (after goku turns SSB) says goku is an enemy worth using his full power on and show his fruits of his training.

Significance: Basically a heavy implication that freeza believed goku can go super saiyan and he would still not need to show fruits of his training.

This shows that Goku is far below 1/50th of SSG,

• Tien, Krillin and other humans on final form freeza - "Wow, he has powered up a lot"
• but on golden freeza "F-freeza is an ab-absolute m-mo-monster"

Significance: Freeza's golden form is tiers above his "final form" which means that the "base" form of goku is nowhere near SSB and hence nowhere near SSG either.

2. The universe 6 tournament:

• Performance against Cabba, frost etc

Frost is nowhere near SSG level as evident by his fight against piccolo.

So, base goku isn't anywhere near SSG level either since he was weaker than FF frost.

• Fight against hit

Now, many people would throw in as an "evidence of 2 base theory" but it is not.

Goku fights against hit in base, hit isn't serious and tells goku to transform. Goku counters hit's time skip and then hit gets serious.

Infact, in this fight, goku shows no "aura" or anything like that.

3. The copy-vegeta arc:

Here, we get to see two fights:

1. (copy) Vegeta in base absolutely demolishes SS3 gotenks and goku matches him

2. Beerus in monaka costume fights Goku on an even level.

Thses two things prove nothing that Goku is anywhere near SSG level. The only thing it proves is that Goku's base is well above SS3 gotenks and around the level of (suppressed) Beerus in beginning of BoG.

4. Future trunks arc:

The fact that future trunks was able to even make SS2 goku exert slightest of effort proves base goku would be nowhere near SSG.

Then we see Zamasu giving SS2 goku issues and he is nowhere near SSG either.

Then again, we see that base black is SS2 to SS3 goku level. Black turns out to be stronger than base goku (due to Zamasu) but nowhere near SSG level despite having goku's body (that too a stronger one than the current goku).

All of these prove that SSG is far above base.

5. The universal survival arc:

The only time goku has fought as of yet is when he fights gohan. While it seems goku is suppressed, he is still exerting effort. If he was anywhere near SSG in base level, he could've finger-flicked SS gohan with ease while heavily suppressed.

Goku's base is well above fat buu tier:

1. The fight against freeza:

Tagoma treated Piccolo way worse than perfect cell could've treated cell games goku. Even if we believe piccolo made no progress sinec buu arc, he still should be close to cell games goku level. So, Tagoma is, at minimum, close to perfect cell's power.

Gohan treated him the same way his kid self treated full power perfect cell. So, he is actualy close to cell games gohan. Hell, I would massively lowball and say he is only half of kid gohan. First form freeza manhandled him. So, by scaling, final form freeza must be well above buu. That means so is base goku.

2. Universal tournament arc:

There is not much to confirm, except heavily weakened Frost being way more powerful than piccolo while holding back

• Frost: "I will come at you without holding back" to vegeta when he tells the tournament organizers to give him a chance to fight frost.

Significance: Frost implies holding back against piccolo.

And this is piccolo after training with gohan for atleast 8 months since RoF.

While this does not prove goku/vegeta's base is above buu, it does prove that they are easily on or above perfect cell level at minimum.

3. The copy-vegeta arc:

What needs to be said? Stomping SS3 gotenks and matching heavily suppressed beerus, both of whom are well above buu, are good enough feats.

4. Future trunks arc:

Several indications here.

• Vegeta blows up ROSAT by powering up, in base form.

It is a clear SS3 gotenks+ tier feat.

• Super Saiyan 2 goku is said to be rivalling a god of destruction. If he was even weaker than someone like buuhan, why would Gowasu say that? Obviously, beerus is more powerful than he thought, so Gowasu corrected himself.

SS2 goku is 100x base goku. So, since SS2 goku is much, much stronger than anything seen in Z, it is obvious that base goku must have to be around if not above buu in base.

• Future trunks while probably barely trying, easily defeats kid trunks (SS) off panel.

Not puts him above buu, but does put him around cell-games self in base, at minimum.

Base and godly base are not any seperate things:

1. Both have the same kind of ki.

Since it is proven that god ki can't be sensed, and regular ki can be, and the only saiyan forms to have god ki are SSG and SSB, both base and "godly" base have the same ki which is never stated to be special.

2. Same appearance

3. It is pure speculation:

Not once in the show is it implied that saiyans have 2 levels of base power. Base means base. It is meant to be a kids show, not be confusing with speculations. If the authors and creators have anything like that in their mind, they would've attempted to tell us.

4. The difference is never noted:

Krillin is one character who always notes power level differences. He noted it when goku came back from whis training to reach a new level (probably above buu)

However, he never notes an extremely notable thing that would be "hey, goku got even weaker than before, millions of times weaker by training in ROSAT for 3 years. He is thousands of times weaker even in Super Saiyan" How much sense does it make?

5. The only few "low showings" can be explained and none of the "high showings" require them to be SSG level or anywhere near it"

Conclusion:

So far, from RoF to universal survival arc, everything indicates that the base saiyans (goku and vegeta) have power level nowhere near Super Saiyan god, and above majin buu / fat buu, and very likely noticeably above SS3 gotenks. This means their power can be somewhere between Buuhan and Vegetto. This is supported by feats and showings.