“By far, the N.F.L. is the crown jewel of entertainment,” he said while showing off the Xbox at the company’s headquarters, east of Seattle. “It has that fan passion, and we have that with the Xbox. And on the sideline, it really showcases what Microsoft can do when it brings its full muscle to bear.”

The question of how to create the “sideline of the future” arose a couple of years ago, said Brian Rolapp, the executive vice president for media at the N.F.L. As Motorola’s deal with the league was coming to a close, league officials thought about things they wanted to improve. One was the black-and-white photos of every play of every game, he said. For years, assistants grabbed the photos off printers on the sideline, stuffed them into three-ring binders and gave them to coaches and players to review. But the photos were grainy and cumbersome to collate and could not be annotated.

The N.F.L. spoke to several technology companies before settling on Microsoft, partly because it could produce a tablet for the sideline and turn the Xbox into a conduit for N.F.L. content. Microsoft, meanwhile, saw the value in getting its products in front of millions of fans.

“I’m not sure where sponsorship deals end and media deals begin,” Rolapp said. “People spend a lot of time on a 30-second commercial trying to convey the attributes of their product. This actually shows it.”

Introduced in the preseason, the tablets have worked largely as designed. Brian Schneider, special teams coach of the Seattle Seahawks, said he liked that the photos were delivered to his tablet in seconds because he often had to chase players running on and off the field. The clarity of the photos and the ability to zoom in help him highlight the blocking schemes and decoys of opposing teams.

“It’s so much clearer; you can get so much more information,” Schneider said at the Seahawks’ training complex. “I used to wait for the photos to arrive, and I’d get antsy. Now, I get the photos by the time the players come off the field.”