Thanks for the feedback. I agree that the radars are fairly confusing, and given that I've gotten that response a few times I might try putting the same data in bar graphs or scatterplots for each statistic.
The reason I've used them so far is that they're good for showing multiple data points at a time, but if they're confusing, then they don't serve the purpose of visualizations.
In regards to the two categories you mentioned, rating increase/decrease is simply how the player changed in rating during the tournament.
Average centipawn loss is a metric I've gotten from lichess, which measures how much (per move) the computer valuation of a player's position drops after their moves.
I'm going to be doing a blog next about more chess-specific stuff, as I don't want this to turn entirely into a stats blog rather than a chess blog, but I really appreciate your feedback regardless as these are topics I'd like to return to in the future.