Complex sentence: After the race, Jeff Gordon (who was involved in the lap-137 accident) was less optimistic about his championship chances: This pretty much does it for us as far as I'm concerned for the championship.
Split into simpler sentences: After the race, Jeff Gordon, who was involved in the accident on lap 137, was less optimistic about his championship chances. Gordon argued, This pretty much does it for us as far as I'm concerned for the championship.