Independent Oakland Ballers minor league club uses metrics, finds winning fan to manage finale

OAKLAND, Calif. (AP) — Colt Rosensweig and her two Doberman service dogs, Caris and Curtis, have been in attendance for so much winning at the Oakland Ballers games she has all the other fans beat.

By the analytics, anyway.

And that has earned her chance to be manager for a day.

The Ballers are taking metrics from the diamond and transferring those numbers up into the stands and their fan base – with co-founder Paul Freedman developing their unique version of “WAR,” or Wins Above Replacement, which tells how many more victories a player provides a team over someone else who might be called into action instead.

In this case, it’s Rosensweig at the top with her “fan value” shining above any other face in the crowd at Raimondi Park. Eligible are those who have attended five or more games and signed up for a “BallerMetrics” profile with the team that uses ticketing data to measure a supporter's impact on the results.

So for Fan Appreciation Day and the final regular-season game against Long Beach Coast on Sunday afternoon, Rosensweig and her pups will be decked out and in the dugout – the 40-year-old professional dog walker working as Ballers manager alongside regular skipper Aaron Miles. He will be Rosensweig's assistant.

“So it turns out that the stats were cumulative, including last year,” she explained from her seat during Friday night’s after receiving the honor. “Last year other than the last game of the regular season when Aaron was just throwing in a different pitcher every inning, we were undefeated … the dogs were undefeated, except for that last game, and I told Aaron about it and he was like, ‘It’s my fault.’

“I don’t know what the record is, but (Freedman) said I’m 2.4 times luckier than any other fans. That’s hilarious.”

Each participant's statistics are updated each game, everything from how many runs or stolen bases someone has seen to Ballers' batting average or longest home run when that person is in the ballpark.

“We believe the fans contribute to our success, so we connected the data to make that case," Freedman said.

Among Rosensweig’s first questions for Freedman: “Does the manager pick the uniform?” She’s partial to the pinstripe pants. But nope, that one’s not her call.

Almost everything else will be.

She gets to write the lineup, exchange it with the opposing manager and make pitching changes. It also will be Rosensweig's decision when to pinch-hit or sub someone out for the defending Pioneer League champions created by Freedman and co-founder Bryan Carmel two years ago just as the Oakland Athletics were departing the East Bay.

“The one thing we we’re not going to have her do is coach third base, just for safety reasons,” Freedman said.

Rosensweig suffers from fibromyalgia, a medical condition that causes debilitating pain throughout her body and can come on at any moment. The dogs are harnessed to help her move around, especially after games when she becomes cold, stiff or wobbly and her body just isn't cooperating.

She earned this opportunity even without being a season ticket holder, something that's in the plans for the 2027 season. She purchased flex packages this year and in 2025 with dear friend Catrina “Cat” Christian.

“I’m not wearing a uniform!” she said emphatically, noting she wouldn’t mind adding an official Ballers jersey to her collection. “I do own a game-worn Steve Sparks jersey, and if anyone sees that quote and knows who I’m talking about, they should get a prize. He’s my favorite ever.”

He was a pitcher with five different major league teams over nine years, playing for the Tigers and spending one year in Oakland.

While Rosensweig never played baseball or softball herself, she was a softball scorekeeper during high school at Menlo-Atherton south of San Francisco for a couple of years “then the baseball team’s head coach poached me to come do stuff with the guys.”

Freedman used his tech background to have some fun developing this stats program. He added an ‘f’ for fan in front of certain categories, such as “fOBP” for on-base percentage.

“What we did is we took our ticketing data and connected it to the player statistics and then we invited people to claim their profiles," he said. “If you wanted to be anonymous it's all anonymous.”

Rosensweig is thrilled — and her numbers are impressive.

The Ballers are 27-10 when she's in attendance, including a 13-game winning streak, and have a team ERA of 4.62, .354 on-base percentage and .472 slugging percentage. She has witnessed 249 runs and 70 homers — Cam Bufford's 425-foot drive being the longest — and four walkoff wins. Six times Oakland has come from behind to win in consecutive games with her there.

Taking part in such a personal way will be beyond meaningful for Rosensweig, who holds fond memories of going to the Coliseum with her father to see their beloved Tigers play the A's beginning when she was a young girl.

Like so many who love and appreciate the loyal Oakland fan base, Rosensweig was hurt by the A's leaving town for West Sacramento as they await the opening of a new ballpark in Las Vegas slated to be done before the 2028 season.

“I love the Ballers. The Ballers have healed my heart from all the awfulness of the A's leaving,” she said. “I wasn't exactly an A's fan. We were there to see the Tigers and when the Astros switched to the American League we were there to see the Astros. I've been going to the Coliseum since I was tiny. This is just wholesome.”

And Rosensweig's presence is paramount.

“She's lucky,” Freedman said, "we need her in the stands.”

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