By Evolving Hockey's RAPM and HockeyViz's Isolated Impact, his defensive results have been pretty bad. Like shockingly bad.His 'pre-concussion' results were also in a 30-game sample size of the softest/fewest minutes he's received in his career.
I don't see the red flags. He's pulling positive goal differentials this year and a positive Corsi from 23 minutes/game of mid-leverage on that Buffalo tire fire with a PDO of 100.
His xG impact relative to teammates was negative in 22-23 in COL, negative in 23-24 pre-trade, very negative in 23-24 in BUF, and slightly negative this season. Of their top-six defenseman, Byram is last in xG% in BUF this season.
Combined with the injury history, yes, many red flags.