Pokemon professor does the math to work out the most damage possible in each generation over the past 28 years, and the number is staggering

gamesradar.com:

Have you ever wondered what the most damage you've ever dealt with one Pokemon attack was? Well, one YouTuber has figured out the maximum possible value of any attack in each generation of the creature capture series.

Unlike a lot of other RPGs, Pokemon games don't actually tell you exactly how much damage you've done. You can work it out, as there is a mathematical formula for it, but the game itself won't display the numbers on your UI. Nuzlockers and others who like Pokemon challenges have tools they can use to show damage, but none of them are going for strategies like this.

Enter King The Luck, a YouTuber who set out on a quest to discover the most damage possible in each generation. You may think you just get the move with the highest base power and have a Pokemon with the highest attack stat use it, but it turns out all the multipliers are far more important than just the base value.

Things like Swords Dance, Screech, STAB, and type weaknesses all play into the calculations. For Gen 1, this means the highest possible damage is obtainable by using a Dodrio with Mimic to learn Swords Dance and then using Sky Attack on a Paras. This gives you STAB and a 4x weakness to Flying for Paras. This would do a whopping 219,048 damage. There's a miscalculation here due to a Gen 1 glitch whereby critical hits ignore all stat changes, even positive ones, so the real value would actually be half of this, 109,525 – still impressive.

That might sound like a lot, but Gen 2 blows it out of the water. It takes some setup, but a Rhydon with Rollout can deal 7,621,632 damage to a Yanma. Talk about overkill. Gen 3 takes the Rollout strats even further and ends up doing 81,865,764 damage. However, this value is also incorrect as it's based on the assertion that in Gen 3 Pokemon eggs hatch at level one – that didn't start happening until Gen 4, so the real number will be a little lower than the one given.

There only appears to be one other mistake, where King The Luck states terrain