While the gameplay "feel" remains identical for top-tier characters like Fox and Marth across all NTSC versions, 1.02 introduced minor technical changes:
The modern competitive standard is (a mod for Dolphin that enables rollback netcode). When you load an ISO into Slippi, the launcher explicitly tells you the version in the top bar. If it says "Melee v1.02," you are golden. 1.02 ntsc ssbm .iso