What is the correct Atk/Sp.Atk multiplier for Orichalcum Pulse/Hadron Engine?

Question

Bulbapedia says Orichalcum Pulse and Hadron Engine increase attack/spattack by (5461 / 4096)x, which is JUST below 1.3332x. However, Showdown gives us 479 attack/spattack on a jolly/timid Koraidon/Miraidon, which have a base of 369, meaning it was implemented as exactly 1.3x.

Who's right? And if Bulbapedia is right, a jolly Koraidon for example would go from 369 attack to 492, had the multiplier been actually exactly 4/3x. However, 5461 / 4096 is 1.3332x, which is JUST but still below 4/3, meaning Koraidon's attack would stack to around 491.96. Would it round down to 491, or to 492 as probably intended?

Comments

For the second part it would round up to 492. Bulbapedia is probably right, but Showdown might have just chosen to simplify the fraction.

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Thanks a lot, guess this company isn't stupid after all. Been playing a single roblox game with over 300 minor glitches like this in merely 15 gamemodes for too long LMAO

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- Pokemon rounds down, so the Attack would be 491.
- The multiplier discrepancy has been reported here as an issue with Showdown: https://www.smogon.com/forums/threads/3663703/page-119#post-9645157

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Wow it would round down from .96? That's interesting

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Are you sure about that? I think Trainer Tower's damage dissertation said Pokemon sometimes rounds 1/2 to 0 and other numbers to the nearest integer.

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I'm confident insofar as Showdown has always implemented it that way and I had only ever read it described in equally absolute terms. But you're right that page indicates otherwise. It doesn't speak about Gen 9, so I suppose it isn't authoritative either.

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@MonkeyBusiness yes, it rounds down for everything. For example, if you have a STAB on, say, Air Slash (75BP), it should be 112.5 BP after the STAB boost, but it's just 112 because of how Pokemon does stuff.

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How do you know this?

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Why does it matter? It's one point of attack either way.

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Because that's what the question is asking for?

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There was a Freezai video that went over phenomenons occuring due to this rounding down thing. I can't get the link bc i live in china and my vpn sucks atm, but I'll get it as soon as possible.

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> 252 SpA Choice Specs Hadron Engine Miraidon Electro Drift (133.3251953125 BP) vs. 252 HP / 64 SpD Toxapex in Electric Terrain: 816-962 (268.4 - 316.4%) -- guaranteed OHKO

According to the Damage Calculator, the multiplier is 1.333251953125, which means Smogon lines up with Bulbapedia.

(5461/4096=1.333251953125)

Answer 1

5461/4096
Much of the damage formula still uses pokeRounding. Orichalcum Pulse and Hadron Engine are both attack modifiers, which pokeRounds aside from when dealing with chained modifiers, where a normal rounding step is taken.

source
For context, "Poke rounding" is a math function that's similar to normal rounding. If the fraction part of a number is less than 1/2, it rounds down to the last integer. If it's greater, it rounds up. If it's exactly 1/2, it rounds down. Chained modifiers are stat-modifying abilities and items that are multiplied and normal rounded in a specific order and then Poke rounded after the last modifier. Examples include overgrow, stakeout, thick fat, choice specs, and thick club. (yes, thick fat and water bubble are attack modifiers, not defense or damage modifiers) Orichalcum pulse and hadron engine are also chained attack modifiers according to the Smogon thread I linked earlier. You can read more about damage and stat calculations here.