While Brock was serviceable to good in that game, I wouldn't characterize as "brillant".  He was 20-27 for 250 yards, 2 TDs on the good side.  On the bad side the Broncos only scored 17 points off the 20th ranked Bears defense that averaged giving up 25 pts per game.  He also failed twice with great field position to even get a first down in the 4th quarter that would have effectively sealed the game.  It took the defense to stop a 2 pt conversion on a TD that allowed Denver to win.  The Brock led Broncos only scored 17 points against the 21st ranked Chargers defense and 12 points against the 22nd ranked Raiders defense.
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Brock had a great 1st half against the Steelers, a GREAT 4th quarter against the Patriots, a good second half against Cincinnati.  Without the last 2, the Broncos don't win a Super Bowl.  But for the rest of the time Brock wasn't very good.  He hasn't put one complete game together yet as a starter for either the Broncos or the Texans.
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Here's hoping he's better.