Walter John Hriniak (born May 22, 1943, at Natick, Massachusetts) is a former catcher in American Major League Baseball who — despite a very brief MLB playing career and a batting average of only .253 — became one of the most prominent batting coaches in the game during the last two decades of the 20th century. As a player, he stood 5'11" (180 cm) tall, weighed 178 pounds (80.7 kg), batted left-handed and threw right-handed.
It would take Hriniak almost four seasons to regain his batting stroke. By then, 1968, he had become a catcher and utilityman, and was no longer a top prospect. But during that season, at Shreveport of the Texas League, Hriniak was managed by Charlie Lau, who soon would become the most celebrated batting instructor in Major League Baseball during the 1970s. Hriniak hit .313 and was promoted to the Braves that September; more important, he adopted Lau's theories about hitting and would use them as the basis for his instruction after his playing career had ended. He also became Lau's close friend.
Hriniak would play only those few weeks in 1968 plus the season at the major league level, for the Braves (by then based in Atlanta) and the San Diego Padres. He appeared in 47 games, batted 99 times, and hit .253 with no home runs, no extra base hits, and four runs batted in. His 25 singles is the post-1900 record for all non-pitchers with no extra base hits. By 1972, he had become a minor league manager in the Montreal Expos organization.
Although the Red Sox had no formal batting coach until Johnny Pesky's appointment to that job in , some Boston players began approaching Hriniak about his theories on hitting, and he began to work with them before and after games. By the early 1980s, Boston players Dwight Evans and Rich Gedman were Hriniak disciples. With Pesky's retirement after the season, Hriniak was promoted to Red Sox batting coach.
Finally, after 12 years with Boston, four as the team's official batting coach, Hriniak moved to the Chicago White Sox in as one of the highest-paid coaches in baseball. (Lau was the White Sox' batting coach in 1984 when he succumbed to cancer. Hriniak wore Lau's old No. 6 in tribute during his Chicago tenure.) Hriniak coached another seven years, through , before opening his own hitting school and becoming a private batting instructor. Former Chisox slugger Frank Thomas, now with the Oakland Athletics, is one of his most loyal adherents. When basketball great Michael Jordan surprised the sports world in 1994 by signing a minor league baseball contract with the Chicago White Sox, Hriniak was the coach brought in to help him with his batting technique. Jordan's baseball career was a brief one, batting only .202 for the Birmingham Barons, a Chicago White Sox farm team.
In 1989, Hriniak authored A Hitting Clinic: The Walt Hriniak Way, which outlined his theories of batting and included participation from Evans, Gedman and Hall of Fame hitter Wade Boggs.