SAN RAFAEL(AP) — “St-riike! ... And we’re talking outside of outside corners.”“Ball!”“St-riiike! ... Inside of inside corners.”Eric Byrnes sat behind the large monitor some 90 feet from home plate watching the screen as the computer told him exactly what to announce for the intimate crowd watching independent league baseball at Albert Field, a full moon in the distance.For the second straight night Wednesday, Supermicro computers in a nearby van and overseen in the ballpark by the former major league outfielder called balls and strikes in what is believed to be the first time in professional baseball an umpire didn’t handle those duties.The visiting Vallejo Admirals and San Rafael Pacifics were thrilled to be part of an experiment using the Pitchf/x automated system designed by Fremont-based Sportvision.The batter’s box is broken down into nine tiny squares, and a yellow spot lights up where the pitch goes, then Byrnes serves as the strike zone umpire by relaying the call. Between innings, he obliges regular autograph requests.“That actually caught more than I thought,” Byrnes quipped into the microphone at one point.Byrnes is a longtime proponent of an automated strike zone, something he insists is “seamless” and barely changes the game.Three cameras record the velocity, trajectory and location of every pitch to determine how closely each pitcher comes to hitting the catcher’s target.“To know you’re getting every single call right, it takes away all the injustices, in my opinion,” Byrnes said.When the Pacifics’ Jeremy Williams struck out looking in the third, Byrnes yelled “Strike three!”The small crowd booed loudly — capacity at the ballpark in the heart of Northern California’s affluent Marin County is about 940. The level is comparable to high Class A ball, with some former Double-A and Triple-A players in the mix.Byrnes stood up and offered: “I’m just the messenger, I mean, yell at this!