Shuffled Tracking in BJ

In BlackJack:
What is Shuffle Tracking?
Does shuffle tracking works?
How hard is it to do shuffle tracking?

Shuffle tracking is an advantage gambling technique where a player tracks certain cards or sequences of cards through a series of shuffles. Shuffle tracking is typically done in blackjack games, although it can be done in other card games. Games with simple shuffles are generally easier to shuffle track than games with complicated shuffles. Thus, shuffle tracking is usually done in 6 or 8 deck shoe-dealt blackjack games, as these tend to have simpler shuffles compared to pitch games, due to the time required to accomplish a complicated shuffle on 6 or 8 decks of cards.

My opinion is that is about as reliable as dice setting. There were several shuffle tracking teams in AC in the 80's. None made a profit,
despite the fact that dealers stood on soft 17 and early surrender was offered. Even when a clumps of cards is identified, the edge is negligible. Surely not enough to overcome the basic HE in the long run.