[1] Yarosz was born the second of eight children on the North side of Pittsburgh, but when he was ten, his family moved to Monaca, Pennsylvania, a suburb twenty-six miles away.

On August 21, 1933, Yarosz won the Pennsylvania version of the world middleweight title from Vince Dundee in ten rounds before 15,000 at Pittsburgh's Forbes Field.

[6] Yarosz defended the Pennsylvania version of the middleweight title against Jimmy Smith on February 12, 1934, winning in a fifteen-round unanimous decision before a crowd of 5,000 in Pittsburgh.

The bout was close but somewhat dull due to too much wrestling and clinching, though Yarosz seemed to hold the lead in all but the late rounds when he looked visibly exhausted.

[11] Yarosz lost both the NBA and NYSAC middleweight title to Eddie Babe Risko who defeated him on September 19, 1935, in Pittsburgh in fifteen rounds before a crowd of 25,000.

[14] On September 21, 1936, Yarosz defeated Risko for the first time in a close ten round split decision, demonstrating the skills of his trainer and the depths of his recovery from his knee injury.

Yarosz showed a definite advantage from the first round, scoring with roundhouse swings, and shining in the seventh where he pummeled the slower moving Risko.

[15] Unfazed by his loss of the title, Yarosz scored an impressive victory over future world middleweight champion Solly Krieger on January 13, 1937, in a ten-round unanimous decision in New York.

[17] On June 6, 1938, Georgie Abrams defeated Yarosz in a ten-round split decision at Griffith Stadium in Washington, D.C. Yarosz lost to the skilled, youthful opponent Billy Conn, another boxer trained by Ray Arcel, on June 30, 1937, in a close twelve round split decision before 13,874 at Forbes Field in Pittsburgh.

But in the remainder of the long bout, Conn caught up and went ahead on points with a brutal body attack and an occasional right and left to the face that exhausted the older Yarosz who became nearly helpless in the closing rounds.

In a fight that had been slow and methodical, the fourteenth opened when Conn dealt a blow to Yarosz's head that made it difficult for him to complete the round, and though he managed, he had little strength left in the fifteenth.

According to the Pittsburgh Press the bout included kidney punching and low left hooks from Conn, and thumbing, gouging and heeling from the gloves of Yarosz.

[21] Future NYSAC world middleweight champion Ken Overlin fell to Yarosz, on March 27, 1939, in a ten-round points decision in Houston.

[26][27] Yarosz died after a six-month battle with cancer on March 29, 1974, at Beaver Medical Center in Rochester, Pennsylvania, a mile and a half North of his home in Monica, where he had been a member of St. John's Church.