Fast National ratings for Tuesday, August 20, 2013.

"America's Got Talent" led NBC to its normal Tuesday wins in all key measures, which isn't particularly notable. 
Among the few notables were the first-ever key demo win for ABC's "Extreme Weight Loss" over FOX's "So You Think You Can Dance."
Otherwise, it was business-as-usual on Tuesday.
Among adults 18-49, NBC averaged a 1.8 rating for Tuesday night, tops in the key demographic. FOX was second with a 1.2 key demo rating, followed by ABC's 1.0 key demo rating, CBS' 0.8 key demo rating and the 0.6 key demo rating for The CW.
Overall, NBC averaged an estimated 6.75 million viewers and a 4.1 rating/7 share for Tuesday night, just ahead of the 6.28 million viewers and 4.2/7 for CBS. FOX was third with a 2.5/4 and 3.75 million viewers, topping the 2.4/4 and 3.42 million viewers for ABC. The CW averaged 1.64 million viewers and a 1.0/2 for the night.
8 p.m. - CBS started the night in first overall with 7.685 million viewers for an "NCIS" repeat, which finished fourth among adults 18-49 with a 0.9 rating. FOX's "So You Think You Can Dance" was second with 3.915 million viewers and won the hour with a 1.3 key demo rating, compared with the just over 3.54 million viewers and 1.2 key demo rating for ABC's "Extreme Weight Loss." NBC's "Hollywood Game Night" encore averaged just under 3.54 million viewers for fourth and a 1.0 key demo rating for third. The CW's "Whose Line Is It Anyway?" remained remarkably steady with 2.25 million viewers and a 0.8 key demo rating.
9 p.m. - NBC's "America's Got Talent" was down from the same hour last week, but still averaged 7.82 million viewers and a 2.0 rating among adults 18-49 in the 9 p.m. slot. CBS' "NCIS: Los Angeles" repeat was second with 5.99 million viewers and fourth with a 0.8 key demo rating. ABC's "Extreme Weight Loss" moved up to third with 3.84 million viewers and to second with a 1.4 key demo rating, compared with the 3.59 million viewers and 1.2 key demo rating for FOX's "So You Think You Can Dance." On The CW, "Capture" rose week-to-week with 1.035 million viewers and a 0.4 key demo rating.
10 p.m. - "America's Got Talent" went up to 8.88 million viewers and a 2.4 rating among adults 18-49 for NBC in the 10 p.m. hour. CBS' repeat of "Person of Interest" averaged 5.18 million viewers and a 0.8 key demo rating for second, beating the 2.88 million viewers and 0.6 key demo rating for ABC's "Body of Proof" repeat.
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.
A long-time member of the TCA Board and a longer-time blogger of "American Idol," Dan Fienberg writes about TV, except for when he writes about movies or sometimes writes about the Red Sox. But never music. He would sound stupid talking about music.