NL over- and underperforming teams

In the interest of balance, just as we did last week with the American League, let’s now take a look at the top teams outperforming their expected record so far this season in the Senior Circuit, referring to the Pythagorean win-loss records at Baseball-Reference.com as well as Clay Davenport's projected third-order wins, which as noted last week is an adjustment for how many wins a team should have won based on how many runs they should have scored and allowed, and adjusted for their strength of schedule:

NL Overperformers

What this boils down to is that the two metrics don’t agree on the extent of the overperformance, although they agree that the Giants, Pirates and Snakes are three of the four teams that are better than expected by two wins or more. They differ on the identity of the fourth: simple Pythagorean expectations tab the Brewers, while the Clay’s interpretive metric puts the Phillies among the "Fortunate Four."

Naturally, this produces a reasonable question: Why the disagreement? In the Phillies’ case, there are probably two chief factors, with a somewhat easy schedule being the first, but a little matter of run distribution looming large. Because of the strength of baseball’s best rotation, the Phillies aren’t going to be caught giving up very many runs, not even on their worst nights. They’ve allowed three runs or fewer in 43 of their 76 games, so even with an offense that has been decidedly mediocre (scoring 4.17 runs per game, barely more than the league average of 4.08), that kind of consistency when it comes to keeping the other guys off the board makes a lot of just-enough hitting stand up in the wins column.

The Brewers are a bit more of a surprise to see, but they get a different sort of break. Like the famously overperforming Snakes squad of 2007, the Brewers have a bad enough crew of back-end relievers to put an exclamation point on some of their losses, especially lately with Sergio Mitre, Daniel Ray Herrera, Marco Estrada, and Tim Dillard being those most responsible. Bolstering a struggling middle relief crew could be a July deadline action item for GM Doug Melvin, because if Ron Roenicke can’t find bridge relief help to hand John Axford and LaTroy Hawkins leads, there’s a division to be lost in that middle-inning morass.

In contrast, the three teams that the two systems agree upon don’t actually have all that much in common beyond their overperformance. The Giants may have an even stronger staff than the Phillies top to bottom, but they have to put up with an injury-riddled offense that ranks among baseball’s worst, which makes the challenge of having their leads stand up that much more difficult. The Pirates are also a weak offense, but they’re getting the benefit of a deep and effective bullpen (despite the loss of Evan Meek to a bum shoulder) that helps compensate for a rotation that Clint Hurdle has to get out of trouble early on. They’re also five games over .500 in one-run games, but a team with an effective pen is going to catch a few breaks in tight contests. Joel Hanrahan you know about, but the Pirates are also getting good work from Jose Veras and Daniel McCutchen.

The D’backs are fairly simple as these things go: They’ve been extremely fortunate in one-run games (16-9), and per Baseball-Reference’s “Strength of Schedule” metric, they’ve had the benefit of one of the easier overall schedules in the majors. That’s not to discount the huge progress they’ve made this season from last, however -- after suffering with a historically awful bullpen last year, this year’s staff is getting useful work from David Hernandez and Joe Paterson setting up J.J. Putz, while the rotation has three starting pitchers reliably getting the game into the seventh. Add in the breakouts of the young veterans we’ve seemingly been waiting on forever to bust out, and they don’t seem that extraordinary as improbable breakouts go, especially after correcting early-season.

What about the teams who aren’t quite so happy about their lot in the standings and have cause for grief? Here again, we’re not seeing a lot of teams doing something shocking. Pythagorean expectations nominate just three teams as much as two games under their deserved lot: the Astros, with an MLB-worst minus-3 in terms of their expected record, while the Reds and Padres are two games under. Clay Davenport’s third-order wins nominate just two teams two games or more below their expected mark -- the reliably luckless Astros (-3.4) and the flopping Fish (-2.3).

Predictably enough, you’ll find all of them in the negative in one-run games, although the Marlins probably deserve some form of extra credit for the majors’ worst record in extra-inning games (4-9). The Astros have had more than their share of things go wrong, but having one of baseball’s worst defenses doesn’t help -- Houston is converting less than 70 percent of all balls in play into outs, a woeful mark that puts them in the company of the Dodgers and Cubs for stumblebummery.

Christina Kahrl covers baseball for ESPN.com. You can follow her on Twitter.