The Royals swept the Dodgers yesterday, running their record under Buddy Bell to 11-4.

They became the fourth team in major-league history to sweep both the Yankees and the Dodgers, both times under Bell. The first to sweep both teams was the 1966 Orioles who took four straight from the Dodgers in World Series. The other two were the 1997 Mariners and the 1998 Angels (by the way, MLB missed the 1966 O's in their analysis).

Of course the Royals are still one of the worst clubs in baseball because of their record before Bell:

They have improved by .473 percentage points under Bell yet far. That made me wonder what was the best improvement under a replacement manager in baseball history. Has any team improved by that much over a full season?

Well, first I limited it to managers who took over a team that was at least ten games into the season. The 1986 Orioles started 0-6 before Cal Ripken Sr. lost his job. Frank Robinson took over and they went 55-100 the rest of the season. That's a .355 improvement, which sounds tremendous but doesn't really capture how the team performed under each manager (which was lousy in both cases). The small sample size obscures that. I also limited the search to managers who had a stint of at least ten games, in order to avoid lucky interim managers.

The results…No one's ever equaled Bell's improvement for a full season. Charlie had the biggest improvement taking the '44 Cubs from a 1-10 record when he started to a 75-79 record at season's end, a 487-point improvement over his predecessors. Here are the best all time:

Now, the biggest improvement in the expansion era:

I had to include Dallas Green and the '79 Phils given that team went on to win the only World Series in franchise history the next year. As for the Royals, let's say that the change of mangers in Kansas City induces a similar improvement to one the Phils witnessed in 1979. That would be a .400 winning percentage under Bell or a 45-67 record. That would give the Royals a 58-104 record overall, still one of the worst teams in the game overall. Oh well.