He began his professional career with the McKeesport Tubers of the
Ohio–Pennsylvania League in 1910 and recorded 18 wins before being signed by the
New York Highlanders in September of that year. In his rookie season he went 14–14 with an
earned run average of 3.35, he also recorded a
batting average of .272 (during the course of the season he played 11 games in the outfield, and also made numerous appearances as a
pinch hitter). Persistent problems with his throwing arm led to a record of 8–16 and an earned run average of 4.47 in 1912. He regained his form the following year, going 9–8 with 2.41 earned run average for a newly renamed Yankees club that finished 37 games below .500. The 1914 season was the best of his career, going 17–9 with a 1.94 earned run average for another Yankees team that finished well below .500. During the course of the season he had numerous run-ins with manager
Frank Chance, resulting in his being fined on several occasions for drunkenness and general poor conduct. Towards the end of the season, Caldwell asked team owner
Frank Farrell to rescind his fines—which by that point accounted for a substantial proportion of his annual wages. Farrell, fearing that Caldwell would follow former teammates
Russ Ford and
Hal Chase in accepting an offer to pitch for the
Buffalo Buffeds of the
Federal League, agreed to let Caldwell off. As a consequence of this, Frank Chance, feeling that his authority had been irrevocably undermined, handed in his resignation as manager of the Yankees. In 1915, Caldwell once again posted a winning record—19–16, with an earned run average of 2.89—for a Yankees team that finished 14 games below .500. He also contributed four
home runs during the course of the season, enough to finish ninth in the
American League in that category, despite having more than 200 fewer
at bats than anyone else in the top 10. The Yankees were a winning team in 1916, but Caldwell had major struggles, both on and off the field. His difficulties on the mound were not helped by his continuing to pitch with a broken
patella. By the end of July his record was 5–12, and he had recorded an earned run average of 2.99. It was at this point that Caldwell, whose
alcoholism had become increasingly pronounced during the course of the season, went
AWOL.
Bill Donovan, the Yankees manager—who prior to this had always turned a blind eye to Caldwell's personal problems—issued a fine and suspended him for two weeks. However, Caldwell failed to return to the club after this period had elapsed and he was suspended for the rest of the season. Caldwell did not return to the Yankees until the following March, more than a week into
spring training. His whereabouts during the intervening seven months, although much speculated on, were never revealed. Donovan and the Yankees owner,
Til Huston, both of whom had strongly criticized Caldwell during his absence, decided to give him another chance, largely influenced by his apparent good condition. However, once again, his performances on the field were overshadowed somewhat by his actions off it. He finished the year 13–16 with a 2.86 earned run average for yet another Yankees team that finished well short of .500. During the course of the season he again served a team-imposed suspension for getting drunk and failing to report for duty. He was charged with
grand larceny half-way through the season for allegedly stealing a ring, and was also taken to court by his wife, who sued for
alimony after he abandoned her and their son. In 1918, Caldwell once again failed to complete a season with the Yankees. Injuries hampered him on the mound, but he still managed to compile a batting average of .291 during 151 at-bats. Prior to leaving the club, Caldwell went 9–8 with an earned run average of 3.06. Caldwell left the Yankees in mid-August to join a
shipbuilding firm in order to avoid military service after being picked in
the draft. Joining a shipbuilding company was attractive to Caldwell, as it was for others, because it offered him the chance of playing baseball for the company rather than actually working on the assembly line. Despite this, the Yankees had not given Caldwell permission to leave the club mid-season and it was decided that he should be traded. In the winter of that year Caldwell was traded to the
Boston Red Sox in a deal that also saw
Duffy Lewis and
Ernie Shore go the other way. Caldwell was released by the Red Sox in July 1919 after a poor start to the season, in which he compiled an earned run average of 3.94 (his record, however, was 7–4). Caldwell finished the season with the Indians, managed by player-manager
Tris Speaker. When he met Speaker to sign a contract, he was initially confused by the wording, as it did not tell him to avoid alcohol after pitching games. Speaker told him it was intentional, aiming for Caldwell to stick to a specific regimen: pitch, drink, sleep the hangover the next day, then come back for wind sprints two days later and batting practice the day after that. Caldwell was struck by
lightning while playing for the
Cleveland Indians against the
Philadelphia Athletics on August 24, 1919; despite being knocked unconscious, he refused to leave the game, having pitched innings, and went on to record the final out for the win. For the six starts Caldwell made that year with Cleveland, he went 5–1 with a 1.71 earned run average. This included the game where he was struck by lightning and a
no-hitter against his former longtime teammates, the New York Yankees, on September 10. In his first full season with the Indians, in 1920, Caldwell went 20–10, with a 3.86 earned run average. The Indians went on to win the
World Series that year, although Caldwell's contribution to that success proved to be negligible. He started Game 3, but recorded just one out, having given up two
hits, a
walk, and an
earned run, before being lifted by Tris Speaker (the Indians did not come back from this, and Caldwell was charged with the
loss). Caldwell's final season in the majors was in 1921, during which he primarily worked from the
bullpen. His record was 6–6, with an earned run average of 4.90. After leaving the Indians, Caldwell went on to spend many years playing for various clubs in the
minor leagues, including the
Kansas City Blues and the
Birmingham Barons. At the age of 43, Caldwell faced 21-year-old
Houston Buffaloes star
Dizzy Dean in the opening game of the
1931 Dixie Series, which Dean had promised to win. Writer
Zipp Newman later dubbed the matchup "the strength of youth versus the guile of the years". Caldwell pitched a shutout and also knocked in the only run to give the Barons a 1–0 victory on the way to winning the series. Caldwell's long-established reputation dissuaded any major league outfit from giving him another chance. Caldwell originally retired from professional baseball on April 20, 1933, having requested such from the Barons. However, he signed with the
Charlotte Hornets in July to attempt a comeback. By September, he had been named manager of the
Keokuk Indians of the
Mississippi Valley League, replacing
Ed Sicking. Caldwell was a very good hitting pitcher in his career, posting a .248
batting average (289-for-1164) with 138
runs, eight
home runs, 114
RBIs and 78
base on balls. He had 10 or more RBI in a season six times, with a career high 20 RBI with the 1915 New York Yankees. He also played at all three outfield positions and first base in the majors. ==Later life==