Use string.sub instead of string.find where possible.

diff --git a/OvaleBestAction.lua b/OvaleBestAction.lua
index 040265b..294e622 100644
--- a/OvaleBestAction.lua
+++ b/OvaleBestAction.lua
@@ -33,7 +33,6 @@ local floor = math.floor
 local ipairs = ipairs
 local loadstring = loadstring
 local pairs = pairs
-local strfind = string.find
 local tonumber = tonumber
 local tostring = tostring
 local wipe = table.wipe
diff --git a/OvaleCompile.lua b/OvaleCompile.lua
index 5706ddc..ed418af 100644
--- a/OvaleCompile.lua
+++ b/OvaleCompile.lua
@@ -31,7 +31,6 @@ local OvaleStance = nil
 local ipairs = ipairs
 local pairs = pairs
 local tonumber = tonumber
-local strfind = string.find
 local strgmatch = string.gmatch
 local strgsub = string.gsub
 local strlen = string.len
@@ -210,7 +209,7 @@ local function ParseFunction(prefix, func, params)
 	end

 	if not paramList.target then
-		if strfind(func, "Target") == 1 then
+		if strsub(func, 1, 6) == "Target" then
 			paramList.target = "target"
 			func = strsub(func, 7)
 		end
@@ -225,13 +224,13 @@ local function ParseFunction(prefix, func, params)

 	-- "debuff" and "buff" conditions implicitly set their aura filter.
 	if not paramList.filter then
-		if strfind(func, "debuff") == 1 then
+		if strsub(func, 1, 6) == "debuff" then
 			paramList.filter = "debuff"
-		elseif strfind(func, "buff") == 1 then
+		elseif strsub(func, 1, 4) == "buff" then
 			paramList.filter = "buff"
-		elseif strfind(func, "otherdebuff") == 1 then
+		elseif strsub(func, 1, 11) == "otherdebuff" then
 			paramList.filter = "debuff"
-		elseif strfind(func, "otherbuff") == 1 then
+		elseif strsub(func, 1, 9) == "otherbuff" then
 			paramList.filter = "buff"
 		end
 	end
diff --git a/OvaleDamageTaken.lua b/OvaleDamageTaken.lua
index 7854ba9..89c3bea 100644
--- a/OvaleDamageTaken.lua
+++ b/OvaleDamageTaken.lua
@@ -59,13 +59,14 @@ end
 function OvaleDamageTaken:COMBAT_LOG_EVENT_UNFILTERED(event, timestamp, cleuEvent, hideCaster, sourceGUID, sourceName, sourceFlags, sourceRaidFlags, destGUID, destName, destFlags, destRaidFlags, ...)
 	local arg12, arg13, arg14, arg15, arg16, arg17, arg18, arg19, arg20, arg21, arg22, arg23 = ...

-	if destGUID == self_guid and cleuEvent:find("_DAMAGE") then
+	if destGUID == self_guid and strsub(cleuEvent, -7) == "_DAMAGE" then
 		local now = API_GetTime()
-		if cleuEvent:find("SWING_") == 1 then
+		local eventPrefix = strsub(cleuEvent, 1, 6)
+		if eventPrefix == "SWING_" then
 			local amount = arg12
 			Ovale:DebugPrintf(OVALE_DAMAGE_TAKEN_DEBUG, "%s caused %d damage.", cleuEvent, amount)
 			self:AddDamageTaken(now, amount)
-		elseif cleuEvent:find("RANGE_") == 1 or cleuEvent:find("SPELL_") == 1 then
+		elseif eventPrefix == "RANGE_" or eventPrefix == "SPELL_" then
 			local spellName, amount = arg13, arg15
 			Ovale:DebugPrintf(OVALE_DAMAGE_TAKEN_DEBUG, "%s (%s) caused %d damage.", cleuEvent, spellName, amount)
 			self:AddDamageTaken(now, amount)
diff --git a/OvaleStance.lua b/OvaleStance.lua
index 9627fd2..b040ae3 100644
--- a/OvaleStance.lua
+++ b/OvaleStance.lua
@@ -16,7 +16,6 @@ Ovale.OvaleStance = OvaleStance
 --<private-static-properties>
 local ipairs = ipairs
 local pairs = pairs
-local strfind = string.find
 local tinsert = table.insert
 local tsort = table.sort
 local wipe = table.wipe