Chi is a boom....probably one of the most confusing parts to understand , but explained like this...
You drafted him at RT. He was pregenerated with a weight that was more friendly to overall at that position .. . Switching him to LT made him a bit heavy for the generic weighting system that values the weight (in pounds) and calculates it affecting the score of his overall.
In other words he was light at RT when drafted changed to LT where he was heavy then in the latest camp he lost even more weight to be light a LT. He will most likely stay around this weight as he stays at LT.
What you are seeing is a 100 rated 100 volatility booming combined with positions changes. If you put him at guard his overall rating would fluctuate right along with weight fluctuations that come along with position changes.
You have a 1/3 chance of booming , busting, or staying the same....the big difference visually is a high rated player has more room to go down and a low overall is just the opposite . ...only because they are the extremes of the scale.
You got very lucky with that pick....imo.. a 100 rated player with 0 volatility is the safer pick, but by no means a better pick.
Before volatility was shown jdb said the further a player had to go (red/blue bars) the more likely he would boom or bust. I found that very useful then and now in who to pick.