Team Defence
Incoming attacks against your selected Pokemon.
Team Analysis
Incoming attacks against your selected Pokemon.
Single-type targets hit super-effectively by your team's STAB types.
Defence checks each incoming attack type against every selected Pokemon. Coverage checks your selected team's STAB types against each single-type defender. Mega Evolutions and Primal forms are included as local battle-form entries.
For each of the 18 attacking types, the defence panel counts how many of your selected Pokemon take super-effective damage from it. The individual numbers matter far less than how they cluster. One or two members sharing a weakness is unavoidable and fine. Three is worth planning around. Four or more means a single well-timed Earthquake, Surf or Rock Slide can take most of your team with it, and no amount of good play fixes that mid-run.
Ground is the weakness worth checking first, because it is the most common attacking type on in-game trainers and it hits five of the eighteen types super-effectively. A team of six that stacks three Ground weaknesses is far more fragile than its raw stats suggest.
The coverage panel checks your team's STAB types against each single-type defender, which is deliberately conservative: it only knows the types your Pokemon are, not the moves they have learned. A Gyarados carrying Ice Fang genuinely answers Dragon, but Ice will not appear in your coverage because Gyarados is not an Ice type. Read a gap as "nothing here gets STAB against that type" rather than "we cannot hit it".
Dual-type defenders are excluded on purpose. Coverage against single types is a clean measure; once you add second types the same move can be 4x, 2x, neutral or nothing depending on the pairing, and an averaged score would hide more than it showed.
When both panels look bad, change the defensive overlap first. A coverage gap costs you turns, and you can usually route around it with a TM or a coverage move. A stacked weakness costs you Pokemon, and in a Nuzlocke it costs them permanently. This matters most at the point where you cannot simply re-pick: locked encounters, a limited box, or a challenge run where the team you have is the team you finish with.
If you are still choosing a team, the team randomizer can force six different primary types, which guarantees the defensive spread this tool is checking for. For the type interactions themselves, the type chart lists every matchup this analysis is built on.