More than a month into the season, the overall defensive picture is starting to take shape. Teams have only played a fifth of their total schedules, but the best and worst defensive teams have already separated by 59 Runs Saved, a total that separates them by approximately six wins.

Last season, the Braves and Blue Jays outpaced the other teams with 70 Runs Saved a piece. After a month, only the Braves have rejoined the top-five, and 11 of their 17 Runs Saved are from defensive phenom Andrelton Simmons, who leads baseball.

Here are the best defensive teams so far this season:

Lost in a controversial offseason in which they traded away Justin Upton, the Diamondbacks upgraded their defense and look like the best in baseball in that department. At 32 Runs Saved, they are already 8 Runs Saved past their total for all of 2012. Free agent acquisition Cody Ross and prospect A.J. Pollock lead their tremendous outfield that has saved 25 runs itself.

The Brewers and Pirates come in fourth and tied-fifth on the shoulders of a few defensive standouts. For Milwaukee, they are Norichika Aoki and Carlos Gomez. Our shallow/medium/deep Plus/Minus splits suggest that the Brewers’ outfielders have positioned themselves deeper than most teams, and it is really making a positive impact. For Pittsburgh, Starling Marte has saved an estimated seven runs in left field and looks like a breakout player both offensively and defensively.

Here are the worst defensive teams in the early-going:

Oakland saved an estimated 16 runs in 2012, but they are off to a terrible defensive start this season. Josh Reddick has just 2 Runs Saved after 22 in 2012, and defensive liabilities at shortstop, second base, and pitcher have pulled them to near the bottom of the league.

The division-rival Angels have been even worse defensively to start the season, but unlike in Oakland, they have not hit and pitched their way around it. With Texas looking strong in every facet, the Angels are going to need better from Mike Trout, Peter Bourjos, and Josh Hamilton, who have combined to cost the Angels an estimated eight runs this season.

Like the Angels, the Cardinals have seen early-season defensive struggles in their outfield. Matt Holliday hits well enough that you can forgive him for costing St. Louis an early three runs. The White Sox, in contrast, have seen little offensive production from Adam Dunn and Paul Konerko, who have combined to cost them six runs at first base.