15 games? That seems really high. That's way more than the difference between the most valuable player in the league and a replacement level player. I have a hard time thinking I'd rather have Maddon than Mike Trout. No I was not suggesting Maddon over CC was equal to 15 games. From very worst manager to very best manager yes 15 games is a possible range (going -7 to 0 to +7) Consider the impacts of setting a lineup, the order, who is in or out, setting of roles, clubhouse impact (setting motivation, creating culture for people to succeed) handling of the pitching staff, when to use the pen or stay with starter, which reliever comes in, bunt vs not bunting, green light vs red on certain pitch counts or stealing while on the bases, to challenge or not challenge calls, arguing (or not) to support or defend his players.... The manager has his fingers and impact in many many things..