The Boston Red Sox's franchise-record-tying 15-game winning streak from early to mid-July remains the longest of the 2026 MLB regular season, establishing the primary driver behind the heavy trader consensus favoring a 13-15 game outcome. No club has approached or exceeded that mark since, with recent form limited to shorter runs such as the Dodgers' current six-game streak and multiple nine- or 10-game surges earlier in the year by teams including the Cubs, Phillies, and Rays. Late-September scheduling, pitching depth across contenders, and the inherent variance in MLB results make a longer streak unlikely at this stage. A surprise late push by a hot team could still extend the mark into the 16-18 range before the playoffs begin.