It's tedious, really.
This is essentially what I do. As I see it, there are only two things that can go wrong. Either you are forced to move your chain of high value tiles off the wall it's next to because movement is impossible in any other direction, which is basically instant death, or when you join tiles in the chain and don't have a new one to move into the lowest value 4th spot and are forced to move the highest value tile in the direction of the other tiles in the chain, which gives you a slight chance of a new tile spawning in its place. Both of those situations, I think, are easy to avoid as long as you're "careful," and so the strategy should easily take you to insane levels, if you know what you're doing and can manage to stay awake.
That, or there's actually no reliable defense and you'll always be at the mercy of luckshit.