Welcome to Sliders, a weekly in-season MLB column that focuses on both the timely and timeless elements of the game.It was March of 1969, in spring training, and a pitcher for the Seattle Pilots issued a walk. No big deal, but it prompted some helpful advice from the Pilots’ bullpen coach to the team’s relievers.“The secret to pitching, boys,” said Eddie O’Brien, “is throwing strikes.”Jim Bouton, one of those relievers, printed the line a year later in his landmark diary, “Ball Four,” a book that delighted in skewering the old guard. For the O’Brien family, though, there is no substitute for elementary wisdom. Eddie’s twin brother, Johnny, would impart the same words to his grandson, Riley, now the closer for the St. Louis Cardinals.“He always kept it pretty simple for me,” O’Brien said recently. “The thing he would always tell me is: ‘Point my foot right at home and throw strikes.’”O’Brien smiled. His grandfather and great uncle were teammates for five seasons with the Pittsburgh Pirates in the 1950s. They wouldn’t have known much about modern data on spin rates, arm angles and sweeping sliders.“I mean, the game was so different back when he played, but it was cool just hearing his stories,” O’Brien said. “He made it sound like it was no big deal, playing with all these legends and just making it sound very casual.”Riley O’Brien’s great-uncle Eddie (left) and grandfather Johnny (right) — pictured on Opening Day in 1953 — were teammates on the Pirates for five seasons. (Bettmann / Getty Images)Through Thursday, O’Brien is tied for second in the National League in saves, with 19. Batters are hitting .037 (1-for-27) against his sweeper, and the Cardinals are holding a wild-card spot nearly halfway through their schedule.“I think the progression of getting him to this spot was kind of giving him the ball and saying, ‘Run with it,’” manager Oli Marmol said. “When we got him from Seattle, we definitely thought the stuff was there. We wanted to get him to believe in his stuff as much as we believed in it.”The Cardinals are getting the best of the 31-year-old O’Brien, but as settings go, Seattle should have been the perfect fit. He was born there in 1995, the year the Mariners first made the playoffs and long after the Pilots had left for Milwaukee. He played at Shorewood High School in Shoreline, Wash., Everett Community College and the College of Idaho.O’Brien’s mother, Kerri Hong, was a flight attendant who sometimes worked the Mariners’ team charter. As Riley made his way through the minors with the Tampa Bay Rays and Cincinnati Reds, she made sure to tell Jerry Dipoto, the Mariners’ president of baseball operations, all about him.“When we had the opportunity to pick him up in a small deal (with the Reds), we did, and she was overwhelmed with appreciation to have him at home and around the family,” Dipoto said. “When he made his Mariners debut, they were all in the ballpark to see it.”Dipoto, an avid baseball card collector, was touched to receive a thank-you note that included a card of Hong’s father-in-law from the 1956 Topps set. Alas, O’Brien’s Mariners debut — in 2022, after a one-start cameo with Cincinnati the year before — would be his only game for the team.At Triple-A Tacoma in 2023, O’Brien posted a 2.29 ERA and 86 strikeouts in 55 innings. But he struggled to follow the family’s No. 1 rule: he didn’t throw enough strikes, averaging five walks per nine innings.When the Mariners needed a roster spot in November 2023, the Cardinals snagged O’Brien from them for cash considerations. They used him for 50 games across the next two seasons and made him closer early this year.While O’Brien has a 4.05 ERA, he has converted 19 of 23 save chances and blown just one opportunity since May 10. He has not appeared before the eighth inning since March.“I feel like pitching in those games brings out the best in me,” O’Brien said. “When the game’s on the line, I feel a lot more game-focused rather than internally focused, where you can start thinking about other stuff. When I’m out there to save the game, it’s just: ‘What can I do to get three outs? What can I do to get us to win?’”For O’Brien, it has taken years to build off his strong start in the Tampa Bay farm system, where he started his career as an eighth-round pick in 2017. After three good seasons, the lost Covid year interrupted his progress.“I didn’t go to an alt-site and I was just at home,” O’Brien said. “I think my mechanics changed, a lot things changed. So those next couple years, when I made my debut at Cincinnati and when I pitched in Seattle, I just didn’t feel like the same pitcher. It was cool to get to the big leagues, but I knew that wasn’t really me. I knew I was better than that.”