How many viewers did " The Big Bang Theory " draw with their season three premier ?
The sixth season boasts some of the highest - rated episodes for the show so far , with a then - new series high set with " The Bakersfield Expedition " ( Season 6 , Episode 13 ) , with 20 million viewers , a first for the series , which along with " NCIS " , made CBS the first network to have two scripted series reach that large an audience in the same week since 2007 .