POKEMON CARD JEOPARDY 2, ROUND 2

Series

100

This series introduced GX cards to the TCG

Sun and Moon

200

This series introduced Level X cards to the TCG

Diamond and Pearl

300

This series features the most Black Star Promo Cards

Sword and Shield (307)

400

This series features the most Holiday sets

Scarlet and Violet (6)

500

This series features a Type of Card that does not have a rarity, is EXCLUSIVE to promo cards, and was playable in the TCG. 

Sword and Shield 

600

This series has the most expensive non-WOTC promo card in a PSA 10. (via pricecharting.com)

Diamond and Pearl, Infernape Level X, $35,197 in a PSA 10.

(https://www.pricecharting.com/game/pokemon-promo/infernape-lvx-dp10#completed-auctions-manual-only)

Eras (Vintage, Mid, Modern)

100

This era is the most expensive. 

Vintage

200

This era is the common grail of most collectors, because it is timely and precious. 

Vintage

300

This era features the most sets.

Mid (60)

400

This era features the most Rarities. 

Modern (14)

500

The first World Championship of the Pokémon Card Game (Internationally) was held during this era. 

Vintage

600

This era debuted fully illustrated cards. 

Mid (Specifically, HeartGold/SoulSilver, being Legend Cards.)