diff --git a/parts/modes/tsd_h.lua b/parts/modes/tsd_h.lua
index 92fa6989..0f396915 100644
--- a/parts/modes/tsd_h.lua
+++ b/parts/modes/tsd_h.lua
@@ -1,8 +1,17 @@
+local gc=love.graphics
 local function check_tsd(P)
 	local C=P.lastPiece
 	if C.row>0 then
 		if C.id==5 and C.row==2 and C.spin then
-			P.modeData.tsd=P.modeData.tsd+1
+			local L=P.modeData.history
+			if L[1]==C.centX and L[1]==L[2]and L[1]==L[3]then
+				P:showText("STACK",0,-140,40,'flicker',.3)
+				P:lose()
+			else
+				P.modeData.tsd=P.modeData.tsd+1
+				table.insert(L,1,C.centX)
+				L[4]=nil
+			end
 		else
 			P:lose()
 		end
@@ -13,8 +22,9 @@ return{
 	color=COLOR.magenta,
 	env={
 		drop=30,lock=60,
-		freshLimit=8,
+		freshLimit=15,
 		dropPiece=check_tsd,
+		task=function(P)P.modeData.history={}end,
 		ospin=false,
 		bg='matrix',bgm='vapor',
 	},
@@ -22,6 +32,15 @@ return{
 		setFont(60)
 		mStr(P.modeData.tsd,63,250)
 		mText(drawableText.tsd,63,315)
+		local L=P.modeData.history
+		if L[1]and L[1]==L[2]and L[1]==L[3]then
+			gc.push('transform')
+			PLY.draw.applyFieldOffset(P)
+			gc.translate(0,P.fieldBeneath+P.fieldUp)
+			gc.setColor(1,.5,.5,.2)
+			gc.rectangle('fill',30*L[1]-30,0,30,600)
+			gc.pop()
+		end
 	end,
 	score=function(P)return{P.modeData.tsd,P.stat.time}end,
 	scoreDisp=function(D)return D[1].."TSD   "..STRING.time(D[2])end,
@@ -32,8 +51,8 @@ return{
 		T>=20 and 5 or
 		T>=18 and 4 or
 		T>=15 and 3 or
-		T>=10 and 2 or
-		T>=4 and 1 or
-		T>=1 and 0
+		T>=11 and 2 or
+		T>=7 and 1 or
+		T>=3 and 0
 	end,
 }
\ No newline at end of file