- Bats Left, Throws Left
Jeffries debuted with the Indianapolis ABCs in 1913 and would spend 12 years with them. He was 4-4 with a 2.49 ERA in 1916, tying Judy Gans for 7th in ERA among top black teams. He hit .301/.363/.384. He fell to .171/.247/.186 in 1917 but pitched well (4-3, 2.49, 9th in ERA). The southpaw posted a 7-2, 4.44 record for the 1918 ABCs and batted .286/.342/.400. He was second in wins among top black western clubs, behind only Dick Whitworth. In 1919, Jim was 0-1 with a 5.00 ERA.
Jeffries struggled as an outfielder in 1920, fielding .898 and hitting .169/.285/.180. On the hill, the 27-year-old was 7-8 with a 3.77 ERA. Jim was better on both ends of the ball in 1921, with a batting line of .259/.331/.297 and a pitching line of 15-13, 3 Sv, 3.03 with a 125 ERA+. He tied for fourth in the Negro National League in wins, behind Dave Brown, Bill Drake and Bullet Rogan. He also tied for fourth in losses, tied for the most saves, led in innings (261), led in hits allowed (240), led in starts (28), led in appearances (42), was second in walks (88) and was 7th in ERA (among pitchers with 100+ IP).
As if he had not been busy enough during the 1921 season, Jim spent the winter of 1921-1922 in the California Winter League with the Colored All-Stars. He hit .254 and went 9-5, leading that league in both games pitched (14) and victories. In 1922, the workload did not let up much as he stopped playing the outfield almost entirely but went 21-11 with two saves and a 3.28 ERA. He easily led in wins (7 more than Rogan), tied for second in losses (one behind Bill Holland), again led in appearances (37), tied for the save lead, led in innings again (205 2/3), was 8th in ERA (between Huck Rile and Phil Cockrell) and tied for 6th with 88 strikeouts.
After two years of a ton of innings, Jeffries never was successful again. He was 0-1 with a 7.50 ERA in just two games for the ABCs in 1923. In 1924, he left the ABCs after going 0-1, went 0-1 for the Harrisburg Giants and was 0-2 for the Baltimore Black Sox. Playing against the 1924 A's, he was 2 for 8 at the plate. He was 0-2 for Baltimore again in 1925.
Overall, Jim was 60-53 in the Negro Leagues. In his peak seasons (1916-1922), he was 58-42 with 9 saves and a 3.27 ERA (115 ERA+). He ranked third in black baseball in wins over this period (behind Dick Redding and Whitworth), tied for first in losses (with Drake), first in games pitched (150), first in starts (95), second in complete games (58, behind Redding), tied for third in shutouts (10, even with Brown), first in saves, first in innings (866 2/3), first in runs allowed (398), first in earned runs allowed (315), first in hits allowed (794), fourth in homers surrendered (23), second in walks (270, 5 behind Whitworth), fourth in whiffs (357), third in wild pitches (11), fourth in hit batsmen (29) and 20th in ERA.