RBO-Low% analysis
RBO-Low% analysis (without OoB, Spazer+Plasma, or GT-Code): (last update: 09.10.2017)
TAS case for NTSC/PAL:
The 5 TAS-Low% categories, 13%PB-PB, 13%PB-Speed, 13%PB-Ice(confirmed for all cases), 13%PB-X-Ray, 13%Charge-Speed, might all be viable options TAS has for RBO-Low%. The items that are shared among all options are: (Ball, Bombs, Varia, 1*M, 1*SM, 1*PB, 1*R-Tank) and in each of the 5 options, 2 more Tanks need to be collected, which could in each case possibly be either (1*E-Tank, 1*R-Tank), (2*E-Tank), or (2*R-Tank)(where Botwoon's E-Tank needs to be skipped). All of the 4 Underflow options would be forced to add (1*M, 1*SM) to the list of shared items, in order to allow for a Crystal Flash. Only the 13%Charge-Speed option (which is confirmed possible in all item-combo cases) can take either (1*M, 1*SM), or (2*SM) as addition to its shared items. And finally, for each of the 5 options, the corresponding category-defining 2 items in its name are added to the item list. All of the Underflow options also need to do Underflow and then exit Draygon's room without killing Draygon (by getting grabbed near the top right door) and can use the Underflow's spark to exit Maridia, to then be able to go and kill Ridley first. But in each of these, at least 1 R-Tank would be required in order to survive Lower Norfair. Viable categories would also not be allowed to kill Phantoon in order to go through Wrecked Ship and Forgotten Highway, before Ridley and Draygon are dead.
It is assumed that in both versions, the Underflow is doable with a cap of 10 powerbombs suitless without using the permanent deceleration. It is assumed that in both versions, the suitless Everest Slopespark from the 13% TAS is doable without Varia with a multi-crab (possibly 4 crabs) hp-drop setup, with no E-Tanks, and only 1 R-Tank.
TODO: It remains to be checked which of the remaining 4 Low% options are possible, and with what item combinations; and the above assumptions remain to be confirmed.
Player case for NTSC:
24%RBO on NTSC is humanly doable with (Ball, Bombs, Charge, ScrewAttack, HighJump, Grapple, 5*E-Tank, 2*R-Tanks, 2*M, 6*SM, 3*PB) and is the current minimum:
https://www.youtube.com/watch?v=rAOWtoh0pcQ]https://www.youtube.com/watch?v=rAOWtoh0pcQ
https://www.youtube.com/watch?v=NNcLJQvAWl0]https://www.youtube.com/watch?v=NNcLJQvAWl0
https://www.youtube.com/watch?v=0VxO-PhOfcI]https://www.youtube.com/watch?v=0VxO-PhOfcI
https://www.youtube.com/watch?v=qqQORhPQ2us]https://www.youtube.com/watch?v=qqQORhPQ2us
For the case in which G-Mode isn't allowed, this item count might stay the minimum, but 23% where ScrewAttack is additionally skipped might be doable.
TODO: A percentage-wise optimized RBO-Low% NTSC playthrough remains to be completed for the case in which G-Mode is used, but it is assumed that 20% would be doable in this case.
Player case for PAL:
PAL has the advantage that heat doesn't do damage as fast realtime-wise while Samus can move with about the same visual speed as in NTSC (most of the time). Hence it might be possible to skip some further Tanks in PAL.
TODO: A percentage-wise optimized RBO-Low% PAL playthrough remains to be completed, for the case with and the case without use of Reverse Lower Norfair entry via G-Mode.