Keep everyone informed of your critical hits.
Thanks to https://wow.gamepedia.com/API_CombatLogGetCurrentEventInfo for the original implementation.
local function OnEvent(self, event)
print(CombatLogGetCurrentEventInfo())
end
local f = CreateFrame("Frame")
f:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED")
f:SetScript("OnEvent", OnEvent)