# Talk:Double Iron Bash (move)

Active discussions

## Flinch chance

I am curious on whether or not for the move Double Iron Bash, that the chance of flinch is individual for each hit. I know that it the chance of flinching is doubled by Serene Grace but not boosted by Razor Fang or King's Rock as it already has a chance of flinching. My question is how does the game calculate the chance of flinching if the opponent is hit by the move. Does each chance have an individual chance of flinching, or is it that only one has the chance to cause flinching, because if each chance has a 30% chance of flinching, that would mean the move has a 60% flinch rate, which seems way too high. I have researched this for a while but could not find any concrete answers, so I am asking it on this talk page. (PeakA (talk) 03:58, 9 April 2020 (UTC))

I don't know the answer to your question, PeakA, but I do want to point out that if both hits have a 30% chance, then the move overall has only a 51% flinch rate, not 60% as you stated. That other 9% is accounted for by the times when both hits individually would cause the flinch; you're double-counting them in the 60% figure. (Easy way to see this: if there were 4 hits with a 30% chance each, of course there could not be a 120% chance of getting a flinch.)(User:Fishdooog 06:22, 24 May 2020 (UTC)
Okay I see why the 51% flinch rate works. But would that mean if a Pokémon with the ability Serene Grace used Double Iron Bash, would the overall flinch chance be 102%? Because if so then that would be a guaranteed flinch on any Pokémon who doesn’t have Inner Focus which doesn’t seem correct.PeakA (talk) 03:38, 25 May 2020 (UTC)
Again, that's not how probabilities work. You don't just add up the overall chances. If this move has two individual 30% chances of causing flinch and if it is affected by Serene Grace, that would result in two individual chances of 60%. In this case, the odds of a Pokémon flinching after being hit by both hits of the move is: the chances from flinching from the first hit, plus the chances of flinching from the second hit, minus the chances from flinching from both hits (otherwise we'd be counting those twice). That would be 0.6+0.6-(0.6*0.6), resulting in 0.84, or 84%. Alternatively, you can calculate the odds of a Pokémon not finching from either hit (which would be (1-0.6)*(1-0.6)) and subtract that from one, 1-0.16, and end up with the same result. Again, keep in mind this is only the case if each hit has an individual chance of causing flinch and if the move is affected by Serene Grace. Suic (talk) 12:36, 25 May 2020 (UTC)