Fast National ratings for Thursday, October 18, 2012.
 
"Two and a Half Men" got a big week-to-week boost which either was or wasn't related to guest star Miley Cyrus. Either way, the venerable comedy combined with "The Big Bang Theory" to help kick-star CBS' easy primetime wins on Thursday night.
 
Meanwhile, after taking last week off for the Vice Presidential Debate, most of Thursday's dramas returned low, including "Grey's Anatomy," "Person of Interest," "Scandal" and "Elementary." 
 
The CW's "The Vampire Diaries" and "Beauty and the Beast" were also down in their second airings. 
 
And FOX continues to get very little value out of this baseball postseason, at least thus far.
 
[Before you get too excited about the "Last Resort" bump for ABC, keep in mind that the network's San Francisco affiliate was airing the Thursday Night Football game in that hour.]
 
On to the numbers...
 
Among adults 18-49, CBS averaged a 3.1 rating for Thursday night, tops in the key demographic. ABC was second with a 2.4 rating, followed by the 1.4 key demo ratings for NBC and FOX. The CW averaged a 1.0 key demo rating for the night.
 
Overall, CBS averaged an estimated 13.055 million viewers to go with an 8.2 rating/13 share on Thursday. There was a big drop to second place ABC's 7.74 million viewers and 5.2/8 and then to FOX's 3.4/5 and 5.42 million viewers. NBC was fourth with a 2.4/4 and 3.53 million viewers, beating the 1.5/2 and 2.38 million viewers for The CW.
 
8 p.m. - The night started with a CBS 8 p.m. rout led by "The Big Bang Theory" (15.395 million viewers and a 4.7 key demo rating) and "Two and a Half Men" (13.595 million and a 4.0 key demo). ABC's "Last Resort" was second with 7.32 million viewers and a 1.7 key demo rating, both up from last week, but remember the warning above. FOX's coverage of the NLCS average 5.32 million viewers and a 1.4 key demo rating in third, beating NBC's "30 Rock" (3.33 million viewers and a 1.3 key demo) and "Up All Night" (3.24 million and a 1.4 key demo). On The CW, "The Vampire Diaries" averaged 2.74 million viewers and a 1.2 key demo rating.
 
9 p.m. - Although it had a stronger lead-in than for its last airing, CBS' "Person of Interest" slipped a little to a still-strong 13.83 million viewers and a second place 2.8 rating among adults 18-49. ABC's "Grey's Anatomy" won the hour with a 3.3 key demo rating and averaged 9.475 million viewers for second. FOX's baseball coverage was third with 5.53 million viewers and fourth with a 1.4 key demo rating. NBC was fourth overall and third in the key demo with "The Office" (4.27 million viewers and a 2.0 key demo) and "Parks and Recreation" (3.43 million viewers and a 1.6 key demo). The CW's second airing of "Beauty and the Beast" slipped to 2.025 million viewers and a 0.7 key demo rating, which The CW notes is in line with the second airing of "The Secret Circle" last year.

10 p.m. - "Elementary" won the 10 p.m. hour easily for CBS despite slipping to 10.84 million viewers and a 2.3 rating among adults 18-49. ABC's "Scandal" was second with 6.42 million viewers and a 2.0 key demo rating. NBC's "Rock Center" averaged 3.45 million viewers and a 0.9 key demo rating.
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.