The networks see the DVR as something of a primetime panacea for ratings, but same-night viewing is still the biggest driver of a show’s numbers.

Just ask some of TV’s top series, which remain as strong as ever in “catch-up” viewing via DVR playback, but have fallen off in the overall ratings because of softer numbers in their regular timeslot. Such shows offer the best argument yet that scheduling and lead-ins still matter.

The ratings declines for ABC’s “Grey’s Anatomy” and “Modern Family” as well as others like Fox’s “New Girl” and CBS’ “Mike & Molly” can at least partly be attributed to significant ratings falloffs this season vs. last for programs that air in the half-hour before them. Networks figured these signature shows would hold up pretty well regardless of lead-in, but this season’s numbers suggest otherwise.

Looking at the Nielsen numbers for all original episodes for which full-week data is available, ABC’s Wednesday 9 p.m. comedy kingpin “Modern Family” is down 15% from last year (6.8 rating vs. 8.0). Yet its “lift” in full-week playback (2.3 ratings points) virtually matches that of last year (2.4).

What’s the difference? ABC changed the 8:30 p.m. show on the night from “Suburgatory” (which averaged a 2.4 same-night demo rating in the 2012 February sweep) to “The Neighbors,” which pulled a 1.75 in the just-concluded sweep. That 27% decline in lead-in is certainly contributing to the dropoff for “Modern Family.”

Similarly, “Grey’s Anatomy” is down 8% overall this year (4.9 vs. 5.3) even though it’s gaining a bit more in full-week playback (1.7 points vs. last year’s 1.6). But again, looking at February as an example, this year’s lead-in for “Grey’s” (1.25 for a combo of drama “Zero Hour” and “Shark Tank” repeats) was 27% lower than last year’s “Wipeout” (1.72).

Among all the declining shows, the biggest difference can be seen in Fox’s Tuesday comedy “New Girl,” whose overall original-episode average of 3.8 is down 27% from last year at this point (5.2) — even though the lift it sees in full-week playback (1.5 ratings points) is the same as last year.

“New Girl’s” average lead-in rating during February (1.37 for “Raising Hope”) was down a whopping 55% from a year ago (3.07 for “Glee”).

And at CBS, Monday 9:30 p.m. laffer “Mike & Molly” is off this season by 18% (3.9 vs. 4.8), but its DVR lift matches last year’s (0.8). Its lead-in average for this season’s sweeps (3.41 for “2 Broke Girls”) reps a 27% decline from last year’s “Two and a Half Men” (4.56).

Contrary to conventional wisdom, there isn’t a lot of variance in DVR playback for shows from week to week; just because a series had a subpar performance in its regular timeslot, it doesn’t magically recoup lost viewers later in the week.

That means it’s important to have viewers tuned in from the start. And even a network’s self-sustaining shows could use that kind of support.