Judging by the standing ovation at Friday’s opening, anyone who loves football might want to rush to see Berkeley Repertory Theatre’s world premiere of “X’s and O’s (A Football Love Story).” But ovations are notoriously slippery gauges of merit, especially on opening nights. Judging by the number that remained seated, “X’s” may not be for anyone with less than a passing interest (sorry, all puns completely unintentional) in the bone-crushing, brain-bashing sport.

Love, actually, might be the root of the problem. Playwright KJ Sanchez and co-creator Jenny Mercein (daughter of former pro player Chuck Mercein) are lifelong, die-hard fans whose faith has been shaken by the ongoing revelations about football-related brain trauma. The result is a docudrama that pretty much takes love of the sport for granted and focuses most of its energy on exploring the downside.

Those people include former pro football players and members of their families, as well as fans and one hard-training aspiring player. Sanchez is the founder of the American Records company, best known for “ReEntry” — a docudrama based on interviews with Marines returning from Iraq and Afghanistan that has toured widely to considerable
acclaim — and almost every word in “X’s” comes from her and Mercein’s interviews with former players, their spouses, sports medicine experts and others. To add to the authenticity, one of the actors is Dwight Hicks, formerly of the 49ers when it was still a San Francisco team.