When we took those starter decks (combined with a few upgrades from booster packs) online and tried to battle on the Pokemon TCG Online rank ladder, we got mercilously crushed by actual decks. They came with supporters that let you draw a few cards, and Pokemon with no abilities that seemed to serve almost no relevant purpose.
Where do you start? A lot of the starter decks you found at stores back then were hardly tournament ready. When I was first getting into Pokemon, I was a little overwhelmed.
