1977 Kansas City Royals: 16
The Royals were created in 1969 and were a contender within two years thanks to an astute front office with outstanding player development acumen. They finished second in the newly-formed AL West in 1971, '73 and '75 before winning their first division title in '76. It would become a habit, as Kansas City would reach the postseason six more times through 1985.
Sluggish out of the gate, the 1977 squad was below .500 as late as June 20 (31-32), at which point the Royals were fifth in the seven-team West, four games behind the Twins. They got hot around the All-Star break (13-2 from July 4 to 22), and took over first place with a 10-game winning streak in mid-August. After dropping three of four, Kansas City kicked off its 16-game run with a 5-4 win over the Rangers on Aug. 31; oddly enough, it culminated in a pair of walkoff wins against the A's in both ends of a doubleheader on Sept. 15, with Pete LaCock singling home Willie Wilson in the 11th inning of the opener and Al Cowens homering in the 10th inning of the nightcap. That was Cowens' fourth homer and 17th RBI of the streak, both team highs; catcher Darrell Porter also homered four times while batting a sizzling .381/.447/.714, and future Hall of Famer George Brett hit .344/.403/.563, with hurlers Dennis Leonard (3-0, 1.00 ERA) and Paul Splittorff (3-0, 1.20 ERA) both dominant.
Overall that meant the Royals had won 35 of their past 39 games. They finished with 102 victories but fell to the Yankees in the best-of-five ALCS when New York rallied for three runs in the top of the ninth for a 5-3 win.