Paul began coaching in Haverford Township at Merion Golf Athletic Association at the age of 16. Merion Golf (Paddock Farms) had several age levels. He began coaching an 8-10 year-old boys team. In 1975 he moved to the 11-13 year-old major division. Following his in-house coaching he began coaching in The Main Line Baseball Association as a Colt, Pony and Cadet coach, winning. His teams won four championships in the 1980’s at the Pony and Cadet levels.
In 1983 he became assistant coach at Haverford High School under head coach Karl Keck. When Karl retired in 1986, Paul was named head coach by Athletic Director ,John Scott. Haverford proceeded in win Central League Championships in 1989, 1993 and 1994. In 1989 and 1993 Haverford played in the final four rounds in district-one, each time losing by one run.
During the summer he coached at Ardmore Manor Legion and compiled a 50-15 record along the way. In 1986, Ardmore Manor went undefeated with a record of 15-0-1. This was the first undefeated American Legion team.
Along with coaching baseball, he was president and vice-president of Merion Golf Athletic Association and Vice President of the Main Line Baseball Association. He began umpiring at the age of 13 and umpired college softball at the age of 20. He also coached at Radnor in the Senior Babe Ruth League and was named tournament head coach.
In 1991 he raised enough money to rebuild the infield at Haverford High School. The team, coaches and parents laid 25 skids of sod on the new field. In 1994 they continued renovations by building dugouts at the field.
Bogosian received coach of the year honors in 2007 and 2009. His teams made the district-one playoffs eight out of ten years beginning in the year 2000. Once again in 2007, Haverford was one game short of being selected to play in the state playoffs.
His teams have received Sportsmanship Awards three times. Several of his players went on to play college ball and one professionally. Mark DiFelice, a 1994 graduate went on to play for the Milwaukee Brewers and Gerard Breslin was drafted by the Phillies.
In 1992, Bogosian began coaching the Central/Del-Val Carpenter Cup team that was later renamed Delaware County. He has been general manager of the team for several years and on the Board of Directors of the Carpenter Cup.
Bogosian was selected to coach the Barrett All-Star team three times during his career. He continues to lend a hand with the Barrett game by taking pictures.
He also serves as a Central League Representative on the District-one Baseball Committee. Baseball has been his life for 42 years now, 32 at Haverford High School where he graduated in 1976.