Sit Here: By the end of this baseball season, Ms. Strub had attended games with about 30 strangers and found that the people she connected with needed her as much as she needed them. She built an online community, bringing together the people she had met in a private Facebook group, calling the project “Strangers to Friends.”

If she couldn’t attend a game — she had to miss a few when her husband, Mike, had brain surgery — she handed off her tickets to strangers who had reached out to her but didn’t know each other.

She said she was “gobsmacked” by the reaction to her post.

“I have made so many friends this summer,” she said. “I have friends that will be my friends for the rest of my life.”