I'll just list in how much their "K" value is
Regionals/States=32 K value
Battle Roads= 4 K value
Prereleases = O K value
The biggest is Regionals since they usually cover one specific region, Angola Indiana is like the Midwest Regional. States are pretty obvious. Battler Roads are all over the place, but are not big events. Then Prereleases may well be the most popular since you can acquire new cards before they come out. Hope I helped.