Controling one's battle power

[ahill1]

There's a debate regarding "what did Vegeta and Nappa do on Earth?". Vegeta, against Cui, said something like him learning how to control his battle power on Earth and pretty much taxed such ability as an "Earthling-thing"... although they seem to have done the same in the battle at Earth, with their auras flaring and comments like "what power!!" surrounding them. Well, here goes an interesting explanation:

What if both Vegeta and Nappa can power up from a resting state, but what they can't do is lower their battle power to an inferior figure to what their "resting state" would be? In such, controling the battle power (what Vegeta has learned after the battle on Earth) goes beyond simply powering up, in which supressing the BP to whatever amount is also part of it? So let's say Vegeta's resting state is 15,000... then he can power up to past these 15k, but can't suppress to below it, whereas someone with this aforementioned ability should be able to.

[DanielSSJ]

To me it seems that what Nappa and Vegeta were doing previously was just sorta flaring up their ki and making it more readily available. Ki sensing isn't 100% precise, and what one can sense seems to rely a lot on how much effort the target is putting forth. Hence Yamcha's line of “Wh…what ki…and he’s not even fighting…” from when Goku showed Trunks his Super Saiyan form, or how Piccolo had to ask whether or not Goku could've beaten Majin Boo with Super Saiyan 3, and how Goku got away with lying to him. The ki is still there and a scouter would still read Vegeta's power level as 18,000, but it's not active or ready to use.

Vegeta's and Nappa's "power-ups" are akin to flexing. Your muscles are still there regardless of what you are were doing, but flexing makes them more visible. On the other hand, the earthlings have the incredibly strange and unique talent to make their muscles magically shrink or disappear outright. If that makes any sense.