The Boston Red Sox's 15-game winning streak from early July stands as the season's longest mark through mid-September, anchoring trader consensus around the 13-15 game range at 96.9% implied probability. No club has approached or surpassed that threshold despite several solid runs, including the Los Angeles Dodgers' active eight-game streak. With roughly three weeks remaining, roster fatigue, expanded playoff implications, and pitching matchups across contending teams make sustained dominance beyond 15 games unlikely. A late surge by a healthy club could still test the upper end of the bracket, though historical patterns show such extensions remain rare in the modern era.