shield vs ncis fall 2013 'NCIS' vs. 'S.H.I.E.L.D.' and 3 more of fall TV 2013's toughest timeslotsThe dust is settling on the 2013 upfronts for the broadcast networks, and as of this moment all 26 new series on the board for fall are potential breakout hits.

Not all 26 will be, of course. The networks will be lucky if two or three of their new shows draw really big viewer numbers. Some will do OK, some just won’t work and some could fall victim to a tough timeslot, of which there are several.

The viewing landscape has changed immensely in the past 10 years, but scheduling does still matter. With that in mind, here’s an early line on which time periods on the broadcast networks could be the most competitive in the fall (all times ET/PT).

See the full network primetime grid for fall 2013

Tuesdays at 8: “NCIS” vs. “Marvel’s Agents of S.H.I.E.L.D.”

In addition to featuring the most all-caps titles of any hour in primetime next season, the 8 o’clock hour will feature TV’s most-watched scripted series, CBS’ “NCIS,” airing opposite maybe the most anticipated new show of the fall, “Marvel’s Agents of S.H.I.E.L.D.” on ABC. It’s hard to imagine anything taking the total-viewer title from “NCIS,” which has averaged better that 21 million viewers this year. “S.H.I.E.L.D.” will probably open big given its connection to the massive Marvel movie franchise, and it could take over the adults 18-49 lead in the time period.

NBC is looking fairly smart to move the Tuesday edition of “The Voice” back an hour and out of the way of the CBS-ABC showdown. FOX’s new comedies “Dads” and “Brooklyn Nine-Nine” and The CW’s “The Originals” could find it really rough.

Mondays at 10: Battle of the new dramas (and “Castle”)

The 10 o’clock Monday spot was a rare one this season where all three network shows were reasonably healthy. “Castle” typically led the overnight ratings in viewers for ABC, and NBC’s “Revolution” was most often tops in adults 18-49 (and got a huge boost from DVRs). “Hawaii Five-0” slipped a little but still drew very respectable numbers (10.4 million viewers, 2.5 in 18-49).

“Revolution” and “Five-0,” however, are moving to new nights in the fall, replaced by “The Blacklist” on NBC and “Hostages” on CBS. “The Blacklist” will likely have a lead-in advantage with “The Voice,” which could help it get ahead of “Hostages.” But it’s “Castle’s” hour to lose at this point.

Thursdays at 9: Star power

There’s little doubt that “The Big Bang Theory” will keep dominating the first hour of primetime on Thursdays — although ABC’s “Once Upon a Time in Wonderland” is an intriguing wildcard. Things really get interesting at 9 o’clock, though, when CBS and NBC each have new comedies featuring long-established stars.

CBS will air “The Crazy Ones,” Robin Williams‘ first series in more than 30 years, opposite “Sean Saves the World” starring Emmy winner Sean Hayes. At 9:30, another beloved star, Michael J. Fox, returns with “The Michael J. Fox Show” on NBC, airing against “Two and a Half Men.” CBS has a pretty big structural advantage here (and “Grey’s Anatomy” and “Glee” still have their fans as well), but it will be interesting to see if the NBC shows can gain any kind of ground.

Tuesdays at 10: A matter of “Interest”

For all of CBS’ success recently the 10 p.m. Tuesday spot has been a little difficult. “The Good Wife” did fairly well there in its first two seasons, but since then nothing the network has put there has lasted more than a season. (“Unforgettable” was canceled after one year in the timeslot, then later revived; it will air on Sundays this summer.) “Person of Interest” is likely to change that — CBS will now be airing the three most-watched dramas on network TV on the same night.

The battle for second place could be interesting. “Chicago Fire” was quietly pretty successful for NBC this season, and it could get a boost airing after “The Voice” on Tuesdays. ABC’s new show “Lucky 7” will probably have the toughest time getting out of the gates, as it ends a full night of new shows for the network.

Posted by:Rick Porter