Part 44: Mini Note 03: Safari Zone Catching RefresherMini Notes 03: Safari Zone Catching Refresher
So how exactly do we catch these Pocket Monsters in the Great Marsh? Well, if you've played a lot in the Johto's Safari Zone, then you already know, cause it's practically identical. Firstly, every Pokemon has a catch rate, which can be modified by the Safari Ball, since it's a x1.5 multiplier, as well as throwing mud or bait. Secondly, every Pokemon that can be found in the Great Marsh or the Safari Zone has a secret escape rate, which is the flat probability they'll flee from battle. This is set depending on the species and only applies to Pokemon found in these zones, as well as being the same across all Gen 4 games. Generally, Pokemon at higher evolutionary stages have lower escape rates and catch rates.
At the start of the battle, the escape rate and catch rate is set to the species' default and if you throw bait, the escape rate is lowered by one stage, but there is a 90% chance of the catch rate being lowered by one stage as well. Similarly, by throwing mud, the catch rate is raised by one stage, but there's a 90% chance the escape rate will be raised also. The rates are lowered and raised in an identical way to stat changes, by -6 or +6, so you'll be receiving diminishing returns the more you go. Just remember that it uses the formula of the five stats and not the accuracy/evasion multipliers. So a Pokemon at +2 will have their catch or escape rate multiplied by 4/2, while being at +6 will multiply it by 8/2. Similarly, a Pokemon at -4 will have their rates multiplied by 2/6.
At the end of each turn, a random number between 0 and 255 is generated and if it's less than the modified escape rate, then the Pokemon flees. When throwing a Safari Ball, the modified catch rate is put into the Gen 4 catching formula and it works it out from there if the Pokemon is caught. All very fascinating sciencey stuff I'm sure. But that's how to catch Pokemon in both the Sinnoh Great Marsh and the Johto Safari Zone.