RNG Manipulation of Method 1 Pokémon
The term "method 1" refers to the way a Pokémon's IVs and PID are created; those wanting a more technical explanation should check out X-Act's article on PID Creation. For the sake of RNG manipulation, you only need to know that the nature and IVs on any given frame for Pokémon generated through method 1 will differ from those generated by any other method. A list of Pokémon that are generated by method 1 in Pokémon Emerald is as follows:
Many of these Pokémon can be obtained through breeding; it is possible to get much better spreads within a reasonable amount of time through breeding than through method 1 resetting. For some players, their main motivation for resetting these Pokémon through method 1 is to generate rare shiny versions (see the section on shiny spreads in the Introduction). For Pokémon not available in the wild, such as Beldum or Sudowoodo, their method 1 forms are used to get parents with good IVs.
It is important to take note that some method 1 Pokémon only become available at certain points in the game, and others need to be obtained in order to progress. Namely, your starter, Castform, and either Latias or Latios must all have their spreads set before you can move forward. The former two are all but impossible to reset for; your starter is obtained at the very beginning of the game, when no Rare Candies are accessible, and Castform succeeds a battle with Team Aqua, which toys with the RNG, giving reset times greater inconsistency. In the case of Latias or Latios, one of these Pokémon must be set via the TV news report in your character's living room, shortly after loading a game upon defeating the Elite Four. In this case, you should be prepared with Pokémon to trap and capture it before defeating the Champion. Of the three, Latias or Latios is most worthy of RNG manipulation; your starter and Castform can both be bred later for better results.
The first step to resetting for method 1 Pokémon is selecting the spread you want. Here are some decent method 1 spreads to help get you started:
For a complete list of frames up to and including 100,000 please download this .csv file.
Once you have selected your spread, you may wish to calculate the stats of your desired Pokémon, using the level at which it is encountered (for this, use your spread's IVs and Metalkid's Stat Calculator). Although optional, when used in tandem with the "IV man", it will effectively ensure that you will not need to use any rare candies if you obtain a Pokémon with the requisite stats. However, there are exceptions to this rule; the stats of Pokémon obtained at low levels give only the most rudimentary information.
A benefit to calculating the Pokémon's stats beforehand is that you can obtain the desired "one under Pokémon" to test your target's Speed and HP. To test Speed, make sure that the Pokémon you send into battle has one less Speed than the Pokémon you want to catch, after taking a Badge Modifier into account; after obtaining the badge that boosts Speed, all your Pokémon's Speed stats are given an invisible modifier of x1.1. For HP, have a Pokémon with one less HP than the maximum of your target use Endeavor. These tricks are most useful when trying to obtain legendary Pokémon; the battles against other method 1 Pokémon do not tend to be as drawn out, so it is not necessary to make sure that you are battling the correct Pokémon. Of course, this is a non-issue for Pokémon that are obtained without a scuffle.
Before you set off to obtain a method 1 Pokémon, be sure to have your party assembled (if you need to engage in battle) with a Pokémon to lull to sleep or paralyze your target, something to False Swipe, and any other utility Pokémon you need. Last but not least, don't forget your Poké Balls, especially if you are using a special kind for aesthetic purposes. Make your way to the Pokémon, and save your game so that you are in an optimal position to generate the Pokémon when your spread occurs. Here is a list of where to save, and the last input for spread generation for all the method 1 Pokémon:
Excluding Kyogre, Groudon, and Ho-Oh, a simple press of the ever-versatile A button is the action that will ultimately cause the RNG to select a spread for your Pokémon. However, in most cases, the RNG does not choose a spread at the instant you perform any of the above actions; the exception is when "spread selected" is listed instead of "last input". For a Pokémon where you only have control over the last input, the RNG keeps cycling through spreads right up until you enter battle. This discrepancy between input and spread selection is caused by the Pokémon's overworld animation or cry. For example, if you press A in front of Rayquaza's overworld sprite, it will utter a cry, then its markings will cinematically flash on the screen before there is a fade to darkness. The RNG is running the whole time, and only chooses Rayquaza's spread once the darkness sets in, immediately before the battle.
All this means for you as the resetter is that you must adjust the time when you input the final command, from the time the spread is normally associated with. Since many good method 1 spreads occur after a considerable amount of time, it is wise to undergo a calibration process before going after a high frame. To do this, select a spread that occurs after a relatively short amount of time; not so short that there is not enough room to adjust, but short enough to let you calibrate fairly quickly. Taking the game's startup into account, a spread that occurs at around 40 seconds or so should do nicely (if you wish to calibrate for the Latias or Latios from the TV, a later spread may be required). Castform is the exception to this rule; it is erratic, and therefore difficult to even calibrate.
Once you have selected a spread to aim for, make sure that the game is on, then grab your stopwatch or timer. Ensure that your stopwatch is set to 0, and that your timer is at the appropriate time. Position your fingers in such a way that you are pressing three of the four buttons to soft reset (A+B+Start+Select), then are able to press down the fourth (A or B is the easiest) and start your stopwatch or timer simultaneously, so the time starts alongside your game. Once the game is reset, mash the A button to skip the introduction sequence and load your file.
How you proceed from here depends on which Pokémon you are resetting for. If you are resetting for a Pokémon that succeeds dialogue boxes, press A to initiate dialogue with the Pokémon or what or whoever gives it to you. In the case of the Latias or Latios set via the television, you must walk down the stairs to initiate dialogue with your parents, and with Castform, you must talk to and subsequently do battle with Aqua Admin Shelly. Press A at a somewhat slower pace to skip through the dialogue until you reach the final box as defined by the list above, and if necessary, make sure your cursor is hovering over the correct option.
The process is similar for Pokémon where you must interact with an overworld sprite to engage in battle. However, in this case, stop pressing A as soon as you load the game, lest you accidentally activate the battle prematurely. Do not worry about this for Kyogre, Groudon, or Ho-Oh; they are activated by pressing a directional button, so you may mash the A button to your heart's content.
Wait at the dialogue box, or wherever else specified, until your stopwatch reaches the time of your spread, or your timer runs out. This is the instant that you press A, or in the case of the aforementioned Kyogre, Groudon, and Ho-Oh, the appropriate directional button; if you are using a stopwatch, be sure to stop it at the same time. If you must capture the Pokémon, now is the time to do so; if it fails the Speed or HP checks you choose to subject it to, feel free to simply chuck a Master Ball to end the battle quickly.
Once the Pokémon is in your possession, take note of its nature, and proceed to calculate its IVs. Depending on the Pokémon in question, this can take a couple or a copious amount of Rare Candies. If you are going after your starter, the only way to get its IVs is to battle an obscene amount of wild Pokémon to level it up, meticulously noting the EVs it accumulates; a similar approach may have to be taken with Castform if you cannot trade over any Rare Candies before you reach the Weather Institute. The Battle Frontier's "IV" man is unlikely to be of much help if you did not hit your spread, unless he concludes your Pokémon has a "flawless" IV; he cannot narrow down your Pokémon's IVs more than an IV calculator the majority of the time.
After your Pokémon's IVs are determined, locate the frame its spread corresponds to. You will then take this frame, and the one you wish to hit, and calculate the difference between the two. For instance, if frame 3,000 was hit while you were aiming for frame 2,700, you would subtract 3,000 from 2,700, leaving a difference of -300. Using the 60 frames per second rule, divide -300 by 60 to get a result of -5. This means that there is an offset of approximately 5 seconds from the time of your input to when your spread was generated; to counterbalance this, you will want to give your input 5 seconds earlier.
From here, you have two options: you may choose to test again to try to get as close to your calibration frame as possible, or you may choose to go after the spread you really want. Once you are ready to do the latter, take the time (or times) you calculated during calibration, and make adjustments as necessary. This is pretty much the same as what you did during the calibration phase, only this time you want to make all the adjustments at once. That is to say, if you found you needed to give your input 5 seconds earlier, then 0.2 seconds later on a subsequent attempt, you would reset 4.8 seconds earlier. Be sure to record this final time; it should not change much as you are resetting for the same Pokémon. However, each method 1 Pokémon has a different pre-battle animation; you cannot use the same results for Rayquaza and Groudon, as their animations do not take up the same amount of time. However, each time you reset for Rayquaza, you can use the same time, if it is close enough to your spread.
It should be said that the calibration phase is not imperative. It is merely an option to save time; it is extremely unlikely to hit a method 1 spread on the first try, due to the offset caused by the Pokémon's cry or other such delays. It is simply quicker to make large adjustments on a spread that occurs after 40 seconds than one at the 40 minute mark. Of course, given that the RNG does not run at precisely 60 frames per second, more adjustments will likely be needed at higher frames, regardless of test runs.
When you are ready to pursue your method 1 Pokémon, repeat the above steps, only use your desired frame, ignoring any references to calibration. Continue to refine your timing until you are hitting frames within close proximity of your spread. Through trial and error, you will be able to hit your spread and obtain the perfect method 1 Pokémon.