Fall TV lineup — The Great Unknown

Shhhh! Don't tell anybody, but TV critics are always sort of guessing when we review new television series.

The fact is that, more often than not, we've only seen one episode before a show goes on the air. Even if we've seen three or four, we have no way of knowing what the fifth, eighth or 11th episode will look like.

Which is why I tend to tell you that a show has great potential if the pilot is good and try to refrain from telling you the series will be great.

This year, previewing the fall season for you is harder than it's ever been. I'd need a functioning crystal ball for a lot of shows ... because we haven't seen pilots for a lot of shows.

A big part of that is because of the Hollywood writers' strike last season, which pretty much messed up the production schedule. Then there's NBC, which decided to save money by going straight from a script to a series, with no pilot in between.

(And that's one of the reasons that the jobs of some of NBC's top executives are reportedly in jeopardy.)

And then there's The CW, which sublet its Sunday night schedule to an outside programming entity, which hasn't shown anybody anything yet.

Sigh.

Based on the relatively limited amount of information available to us right now, here's what to expect this fall from the broadcast networks:

ABC has been making lots of pilots for new shows, but because of the strike, those shows are all going to be midseason replacements. This fall, the network is putting most of its effort into relaunching its Wednesday-night schedule and the three series that debuted a year ago but were cut short by the writers' strike — "Pushing Daisies," "Private Practice" and "Dirty Sexy Money."

(They return Oct. 1.)

As a consequence, ABC is introducing only two new series this fall. They are:

Life on Mars (Thursdays, 9 p.m.) is based on the British series of the same title.

Jason O'Mara stars as a present-day police detective who wakes up after a car accident and discovers it's 1973.

The original pilot was scrapped, the entire cast (with the exception of O'Mara) was replaced and new producers and writers were brought in. That's not a good sign ... but we'll just have to wait and see. (Debuts Oct. 9)