Welcome to Smogon! Take a moment to read the Introduction to Smogon for a run-down on everything Smogon, and make sure you take some time to read the global rules.
I posted this on a different forum and was referred to this thread. The following is copy-pasted from said forum
"Q: From Gen 3 to Gen 4, which 'mons were most affected in tier-lists (up or down 2 or more tiers?)?
This question needs a bit of framing to be fair. My goal right now is to set up a...