Otto Hess was born in Berne, Switzerland and emigrated with his parents to the United States and served in the US Army at the outbreak of the Spanish-American War.

He returned to Cleveland, rechristened the Naps, in 1904 and was regarded as a promising young pitcher and finished the year with a 1.67 ERA, completing 15 of the 16 games he started, including four shutouts.

While in Kansas City Hess had gained a reputation as a hitter with some power, which led him playing in the outfield also. However, he batted just .120 for the season.

Starting 25 games in 1905, Otto won 10 and lost 15, but pitched four shutouts. Despite his poor batting average the previous season, he did double-duty role as an outfielder and responded with his best season with the bat, hitting for a .251 average and two home runs.

1906 was the high point of Otto’s career. He was a workhorse, pitching in 43 games for a total of 333 innings, but after starting seven of the team’s 26 games in August, he showed signs of being overworked. He bounced back however, by shutting out the A's in September, 5-0, and carrying a no-hitter into the ninth inning. Otto finished with a 20-17 record including seven shutouts and a 1.83 ERA).

Otto had reached his peak and the next two seasons brought only disappointment culminating in his return to the minor leagues.

He went on to pitch for New Orleans of the Class A Southern Association from 1909 to 1911 and was one of the league’s best pitchers. At the end of the 1911 season, the Boston Rustlers, soon to be rechristened the Braves, acquired Otto.

With the Braves in 1912, he seemed destined for a minor league berth again. But in fact, he became a mainstay, along with Hub Perdue and Lefty Tyler, even though they were on the National League’s worst team, finishing with a 52-101 record.

Aside from a one-hitter against Chicago in May, Otto struggled through the first months of the season. By late August he had a 4-17 record, but then suddenly became the pitcher who had shown such promise a decade earlier. He concluded the year with eight straight wins, finishing by a 14-2 victory over Philadelphia and ended with a 12-17 record and a 3.76 ERA. Considering his dreadfully slow start and the Braves’ dismal record, he was assured of his return in 1913.

New manager George Stallings, set about rebuilding the Braves into a contender and cleaned house over the next two seasons. In 1913 Otto lost 17 games while winning only seven. With Bill James and Dick Rudolph joining Lefty Tyler as a trio of talented young starters, his days as a regular starter were ending.

By 1914 Otto would be among only five members of the woeful 1912 team who were still on the roster. While Rudolph, Tyler and James would win 69 games, the Braves other pitchers would be forgotten, winning just 25 games among them. Otto, the 35-year-old veteran, would be described by Stallings at season’s end as the team's old reliable.