I had just started the toe decreases on this sock, when suddenly I had not a strand of 4 ply yarn but a cluster of plies. You may be able to see that some of the "yarn" visible on the ball is this stuff, and some (deeper in) is perfectly normal yarn. There's over seven yards of this, (when I took it off the ball to measure it) although I think there's enough normal yarn to finish the toe, after I tink back to a likely area.
In this closeup, you can see the four plies that--in the rest of the ball--were indeed twisted together, but here aren't. I'm trying to tell myself that 7-8 yards of this stuff will be useful. Right now, however, it's a nuisance.