Football is the best sport to watch while reading, because there's a 40-second break between plays. So you can read for a while, then watch the action, then go back to reading.
Baseball is also a great sport to watch while reading, because it has a 30-second break between pitches.
Soccer is a terrible sport to watch while reading. Not only does it lack any breaks, but the sport is boring as fuck. I guess I can rephrase that as: "Soccer is a terrible sport to watch."