Pet Trap Success Rate

A recent WarcraftPets forum topic sparked my interest. How is the percentage increase in a successful chance to trap a pet applied? Is is 20% of the total, or 20% of the previous attempt? I'm referring to the basic trap, but the formula would probably still apply to upgraded traps.

After doing some searching on the Pet Battle forums, it appears that the general consensus is that the 20% is of the previous trap attempt. Whether or not the proper term to describe this is "additive" or "multiplicative", I have no idea. Math was never my strong point lol.

So for example, rather than simply multiplying 20% by 5 attempts to reach a 100% guaranteed trap, the 20% would be taken from every attempt prior.

Let's say the trap has a 10% chance to land, but you miss the first time. 20% of 10% would be 2%, which means your next attempt has a 12% chance to be successful. Unfortunately, you miss again. This time instead of taking 20% from 10% and simply adding it, you would take it from 12% (your previous attempt). 20% of 12% comes out to be 2.4%. Add that to 12% and your next trap should have a 14.4% chance of landing.

Note: Naturally I have no idea what the actual starting point is for a successful trap. Just pretend it's 10% for the sake of this example. :P

This would continue on until you successfully trap a pet, you reach 100%, or if the pet heals itself and/or your pet dies. With the two latter situations, it's possible that the trap success rate resets.

I'm no expert on formulas, WoW theorycrafting, or any of the above, but this does seem to make sense based on personal observation. If the trap success rate is a flat percentage increase, it would only take 5 tries. This is not always the case, though.

If anyone has done further research or has some insight into how the traps work, feel free to share in the comments! I'd love to learn more about this.