q3 answer to andrew official mar-3-2019

To answer the question, you need to maximize the net stat change. Every nature provides a 10% increase and a 10% decrease of base stats. A nature can only be applied to a single Pokemon, which takes that Pokemon's base stats. To maximize this stat potential, you would want a nature that provides a 10% increase to its highest base stat and takes the 10% decrease to its lowest base stat. Because we're dealing with percentages, we can just look at the stats directly because the nature boosts are just proportions of the stats themselves. Stats are derived off of base stats, and it doesn't matter, but you can assume level 100, and base stats are what vary between Pokemon species when it comes to natures. This question comes down to not just identifying the Pokemon with the highest base stat, but also the highest difference in base stats between the pokemon's highest base stat and its lowest base stats.

Across the board, Shuckle meets this criteria at having the highest Defense and Special Defense at 230 and a base speed of 5. Maximizing Defense / Special Defense while minimizing speed produces the highest net stat value. The only other Pokemon that have any base stat of 230 are Aggron-Mega and Steelix-Mega, but their lowest base stat is higher than 5, which means that when it comes to selecting which stat to minimize, the net increase must be smaller. The natures that increase Defense or Special Defense while lowering Speed are Relaxed and Sassy.