When calculating QBR, “garbage time” plays are discounted 30% and screen plays are given as less credit to the QB vs deep plays. Most of everything Barnes did well came after the game was decided, down by 21 late in the 4th, where qbr takes into account that the defense is no longer playing aggressive. Additionally, most of Barnes’ completed passes were short screen style throws. Cam’s QBR would be largely calculated while the game was still undecided, not discounted the 30%, while he also made several “clutch” plays that raises QBR. If Barnes’ small amount of successful plays would have happened before they went down by 21 to keep the game competitive then his QBR would have been higher.