Seybold was born in Washingtonville, Ohio.[1] He started his professional baseball career in 1892, and over the next few years he played in the Pennsylvania State League and Atlantic League.[3] In 1896, he had a breakout season, hitting .352 at Lancaster, and in 1897, he led the team to the pennant[2] by slugging a league-leading 14 home runs.[4] Seybold led the Atlantic League in homers again in 1898 and was leading in 1899 when he was purchased by the Cincinnati Reds.[2]
Seybold made his major league debut on August 20.[1] He did not hit well in Cincinnati, and returned to the minors in 1900. He led the American League in home runs, with 9.[5] Seybold then got his second shot in the majors in 1901, with the Philadelphia Athletics, and this time, he stuck. That season, he hit .334 and had a 27-game hitting streak in July and August.[2]
In 1902, Seybold batted .316 and set career-highs in home runs, with 16, and runs batted in, with 97.[1] The home run total led the league and stood as the AL record until Babe Ruth broke it in 1919.[6][7] The Athletics also won the pennant. In 1903, Seybold's batting average dipped below .300; however, his OPS+ stayed at exactly 138, and he ripped a league-leading 45 doubles.[1] Seybold continued his solid hitting from 1904 to 1907. In 1905, he played in his only World Series, which the Athletics lost to the New York Giants; Seybold went 2 for 16 at the plate.[1]
In 1908, Seybold tore some ligaments in his leg sliding into home in a pre-season game at New Orleans.[8][9] He left the team in June 1908 saying, "I feel that I cannot do myself justice. I have decided to quit for the season."[9] He later returned to the team, but struggled the rest of the year, batting just .215. He played his last major league game on October 7, 1908.[1] In December 1908, Philadelphia manager Connie Mack announced that he was releasing Seybold.[10]
Seybold then played and coached in several minor league and industrial teams for a few years.[2] In January 1909, he signed a contract to play for the Toledo Mud Hens,[11] but injuries continued to slow Seybold during the 1909 season.[12] From 1910 to 1911, he coached industrial teams in Jeanette. On April 4, 1912, he signed with the Richmond Rebels of the United States Baseball League.[13] His baseball career ended with the demise of the league in June.
At the end of July 1919, Babe Ruth equaled Seybold's American League record of 16 home runs in a season;[14] Ruth went on to hit 29 homers in 1919.[15]
Seybold was married but had no children. His wife, Wilhelmina "Minnie" Heitz, died in 1917.[2] In his later years, Seybold was employed as a steward of a social club (Fraternal Order of Eagles) in Jeannette, Pennsylvania.[16] In 1921, Seybold was driving a car when it overturned at a sharp curve on the Lincoln Highway east of Jeanette;[16] he was killed instantly.[2] He left an estate valued at $20,000.[17] Seybold was buried next to his wife at Brush Creek Cemetery in Irwin.
