What is the chance of catching an Articuno in a Quick Ball?

It happened a long while ago, but I found a shiny Articuno on my HeartGold Version. I threw a quick ball at him, and to my surprise, it stayed inside!

What are the odds of this happening?

EDIT: it was level 50

Pleaselog inorregisterto add a comment.

Here is the formula for seeing what is the chance that a Pokemon will be captured:

CatchValue = ((( 3Max HP - 2HP )(Catch RateCapture Rate ) / (3Max HP) )Status Modifier

Here:

CatchValueis the chance that we want to know

Max HPis the maximum HP that the Pokemon has at the time. Here, I took HP IVs as 18 (average) and EVs as 0, and a neutral nature. This ends with Max HP as159.

HPstands for the amount of HP the Pokemon has at that very moment. Since this is the first turn, the Articuno was not damaged, and the HP is the same as Max HP i.e.159

Catch rateis the rate at which a Pokemon is usually captured. Articuno’s is4

Status Modifieris the status the Articuno has at that time. Here we take that as1, as it is the first turn.

Most importantly,Capture Rateis the chance at which a ball can capture a Pokemon. Since this is a Quick Ball and it is the first turn, it’s value is3

After doing all the math,

So that means it is pretty low, and you got very lucky indeed.

Hope I helped!

You have a 1.598% chance of capturing it per ball. Thus, you have at least a 50% chance of catching it within 44 balls and at least a 95% chance of catching it within 186 balls.

source