Fast National ratings for Thursday, August 12. 2010.
 
The two-hour finale of "So You Think You Can Dance" helped FOX win Thursday night in the young adult demo, but procedural repeats and the late-summer rise of "Big Brother" kept CBS on top overall.
 
Among adults 18-49, FOX averaged a 2.4 rating, holding off the 2.0 rating for CBS in the key demo. ABC was third with a 1.5 rating, with NBC's 1.2 rating and the 0.6 rating for The CW following.
 
Overall, though, CBS averaged an estimated 7.878 million viewers to go with a 5.0 rating/9 share. FOX was a solid second with a 4.3/8, with ABC's 3.5/6 in third. NBC's 2.2/4 was fourth, while The CW trailed with a 0.9/2.
 
CBS started the night in first with a 4.8/9 for "Big Brother," which also won the hour in the key demographic with a 2.6 rating, both up over last week. FOX's "So You Think You Can Dance" finale had a 4.0/7 in its first hour for second. ABC's repeat of "Wipeout" was third, topping the 2.1/4 for NBC's repeats of "Community" and "30 Rock." On The CW, a "Vampire Diaries" repeat had a 1.0/2 for fifth.
 
A "CSI: Crime Scene Investigation" repeat had a 4.8/8 for CBS in the 9 p.m. hour. FOX's "So You Think You Can Dance" had a 4.7/8, but beat CBS in total viewers and also won the hour in the key demo with a 2.7 rating. ABC's new "Rookie Blue" was third with a 3.8/6. NBC's "The Office" and "Parks and Recreation" repeats did a 2.0/3 for fourth. The CW's "Moonlight" encore was fifth.
 
CBS won the 10 p.m. hour with a "Mentalist" repeat, which did a 5.3/9 and a  1.7 demo rating. ABC's "Boston Med" was second with a 3.2/6, leaving NBC's "Law & Order: Special Victims Unit" repeat in third.
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.