At the time, network executives fiercely resisted the change, fearing that they would never get credit for recorded shows because viewers would skip through all the commercials. But the figures show otherwise.

“It’s completely counterintuitive,” said Alan Wurtzel, the president of research for NBC. “But when the facts come in, there they are.”

Almost across the board, the gains for playback are growing. The best preseason estimate for the current season, said David F. Poltrack, the chief research officer for CBS, was about a 1 percent increase from playback over the live program for the networks combined. Instead, many are in the range of 7 to 12 percent, with some shows having increases of more than 20 percent when DVR ratings are added. The four networks together are averaging a 10 percent increase.

“It’s the magnitude that’s really surprising us,” Mr. Poltrack said.

In the 18-to-49 group of viewers  the one prized by networks because most ad sales are directed there  Fox has the biggest percentage increase, from an average rating of 2.39 (which translates into about 2.5 million viewers) for its live programs to a 2.71 rating (about 3.1 million viewers) when the three-day DVR playback results are added in.

Image DVR results added 26 percent to live ratings for “The Office.” Credit... Trae Patton/NBC

The numbers for ABC were a 2.5 rating live (2.87 million viewers) to a 2.81 (3.27 million) after three days. CBS had a 2.62 live (just over three million) and a 2.79 (3.2 million) after three days. NBC had 1.79 live (2.05 million) and 1.91 (2.19 million) after three days.

Individual shows have gained substantially. “House,” second among all shows in its live program rating (to “Grey’s Anatomy” on ABC), became the top show in terms of commercials viewed within three days with a 5.68 rating (about 6.53 million), gaining almost 18 percent. NBC’s comedy “The Office” had one of the single biggest gains  26 percent from its live program rating  to 3.92 (4.5 million) for its rating including playbacks.