Most Pokemon are not meant to be defenders (e.g., Alakazam, Tangela, etc.) and only around 20–25 Pokemon currently released are good defenders worth putting in gyms. If the Pokemon is not on our Defenders Tier List, it is likely not a good gym defender.

A moveset's defensive ranking is generally based on its maximum damage output against an array of their most common counters.

Moves that perform well against a Pokemon's counters (e.g., Zen Headbutt on Blissey against Fighting-types) are given more weight when ranking defensive moves. These moves force attackers to dodge, instead of spamming attacks while absorbing the damage.

High-damaging quick moves are better than high–energy-gaining quick moves, since a majority of sub-par defenders will most likely die before using their charge move. Note that this is not always the case with tankier Pokemon such as Blissey and Snorlax.

Multiple-bar charge moves are better when a Pokemon is less likely to survive long enough to successfully execute a sometimes more powerful lesser bar move. Again, a different case for tankier Pokemon.

A move's dodge window has lesser influence now that more players are comfortable with dodging.