I have no proof,,only theory,,but i think some of the casinos use loaded dice,,they hand u the five dice at the start of your roll and i think mybe one or two may be,,once i was on a fairly decent roll and one of the dice bounced of the table ,,you guys know what im talking about and i yelled out same dice,,,,yet the stickman immediately drooped all the dice and handed me new ones. i complained that i asked for same dice and even though i was standing twoo off and he clearly heard me he said he didnt anyhow within two more rolls i sevend out,,,,same thing happened a few days ago i was at a casino and this young girl had a really good long roll and one dice went off the table she called same dice and got them back,,her roll continued,,then again a dice hit the floor and she didnt yell out same dice,,then the gave her the remaining four the very next roll was a seven..then the table went ice cold,,it seemed as if every shooter kept hitting seven naturals then a point and then seven outs it seemed like the dice or picking the wrong combination in dice led to alot of seven outs ,,im not awhiner and i play for fun but the rest of that night i saw a pattern i just stop betting that night and im rethinking going back to that casino to play

honestly, its hard to say but i always tell them before i roll, if any dice go off table, i want the same dice
that way they cant say they didint know, also, as it happens, i make sure to say it loudddd and clear
but eho knows, they may deft be ... maybe heavier on certain edges or something
because ive seen the same things you talked about