The worn sheet of paper is decorated with carefully traced squares that look like a calendar, with numbers in each corner. Every other square is shaded to look like a chess board. 
     In assorted squares are smaller, taped squares with letters like KN, P, and B, some bold, some not, scattered throughout. The Ks rest evenly on opposite squares, across from one another. 
     The sheet marks a year and a half of Paul Karrer's interaction with his former student "Rojelio" (not his real name), as the pair exchanged letters playing "prison chess" through the mail. The game began sometime in 2007, when Rojelio was serving time in Corcoran State Penitentiary. 
     Really, the game began about 15 years earlier, when Karrer was a fifth-grade teacher at Castroville Elementary School and his young charge Rojelio took a keen interest in the game. Karrer had taught all of his students, but Rojelio was especially drawn to it. 
     "He'd show up at my door at the end of the day, with his board and ask if we could play," remembered Karrer, sitting in a restaurant with Rojelio, a chess board set up between them. "Mind you, I was younger with a wife expecting our first child, and he would come up to me and it was just the cutest thing." 
     Those were more innocent days, before the gang lifestyle and the bad decisions and the hard times all caught up with Rojelio. 
     On Thursday, the pair will record a segment with "Story Corps," a National Public Radio program that explores stories of relationships. 
     There is no word on if or when the piece might run. 
     Now 25, Rojelio is three months out of the penitentiary. His head is clean shaven, and he sports matching tattoos behind each ear that extend the length of his thin neck. Chinese characters, translated they read as an ancient proverb. 
     "Only death can set me free," he said, his tone easy as he explains the meaning. 
     At age 13, Rojelio began his life of incarceration, convicted of 23 felonies. Among the charges were arson, battery and attempted murder. 
     He graduated from the California Youth Authority to the penitentiary at age 16. Inside, he was placed in a solitary confinement wing, getting "23&1," meaning 23 hours of confinement and one hour outside. 
     "Sometimes you didn't get the one," he said. 
     On the inside, Rojelio retreated to the friendly confines of chess. He would challenge other inmates, winning noodles or candy bars in side bets and entering prison tournaments along the way. 
     In the solitary confinement wing, he sat in a cell between mass murderer Charles Manson and Robert Kennedy's assassin, Sirhan Sirhan. He would play chess with each man, but it was hardly pleasant. 
     "They would cheat a lot and argue," he said. 
     It was Rojelio who first reached out to his former teacher, after his mother relayed a message that Karrer had asked about him during a chance meeting. 
     The first few letters were simple pleasantries. Soon, Rojelio was sharing his personal experiences, his dark past. Karrer responded with words of hope and encouragement. 
     Sometimes Rojelio's letters were intercepted and not sent at all. Eventually he took to smuggling out his correspondence. 
     Rojelio suggested they play chess by mail. He drew up the board and pieces, similar to the ones prisoners use on the inside. They are not allowed to use real chess pieces. 
     "Even with the plastic (pieces), you could melt them down and throw them in the toilet with some feces for a few days and make a little spear," he explained. 
     Through chess, their bond has solidified. 
     Despite the long time served, Rojelio is upbeat and carries himself with confidence. Karrer admires his charisma. The pair share a bond — with Karrer the protective watcher and Rojelio the appreciative recipient of good will. 
     Karrer worries about his former student. The pull of the gang lifestyle is great, and he knows Rojelio might be helpless against it. 
     Rojelio, to his credit, has tried to look for the positive. He's measuring his steps, much like the game he loves playing.
     A recent night out presented one such test. Rojelio said he was at a bar when he ran into some prison guards who did him wrong on the inside. 
     His instincts told him to strike quick, but then he assessed the situation. 
     "If I would have made a wrong move, I would have lost my king," he reasoned. "I've got two strikes against me, I would have been charged with assaulting a peace officer. It wasn't worth it." 
     Karrer hopes the best for his student, but knows it's up to Rojelio to make the right choices, regardless of Karrer influence. 
     "In chess, like in his life, he evaluates a lot," said Karrer. "He knows it's all about how you use the pieces and the moves you make."