NL Update: Four Weeks In

RS/G, RA/G- Obvious. Through games of 5/6.
Pyth- Current Pythagorean W%.
Current- Team strength in regular sim; about 92% preseason PECOTA/CHONE, 8% current Pyth.
Div%- % of time team wins division in regular sim.
Diff- Difference between Div% last time and currently.
Vegas- % of time team wins division in Vegas-adjusted sim. All I did was take their preseason PECOTA/CHONE W% and add half of the difference listed here. For example, the Rangers, with their +0.30 difference, go from 0.448 to 0.463.
Div- Best "to win division" odds currently available for each team, taken from Bookmaker, SportsBetting, and BetUS.
Site- Location of those odds.

PECOTA had Oliver Perez posting a 4.29 ERA and 19.3 VORP, which is worth taking into consideration with respect to the marginal edge the Mets have here.  Although they are +125/-180 at Matchbook, with over $1,000 available at -210, so +200 is probably slightly +EV, if not worth tying your money up for five months for.  They are also having a field day against Jamie Moyer as I write this.
It's always fun when regression to the mean hits even harder than expected.  On July 3, 2005, the Washington Nationals were 50-31, 5.5 games up on the Braves in the NL East.  Having graduated from high school about a month prior, I didn't know a ton about sabermetrics at that point, but I did know that a team that had outscored their opponents by a grand total of two runs was unlikely to continue to win 62% of their games.  In fact, PECOTA had the Nats winning 74 games last year, so they would've been expected to play about .468 ball the rest of the way, finishing 88-74.
That didn't quite happen.  As you probably remember, Washington fell off a cliff right at the halfway point, winning 19 of their next 54 games (35%) and 31 of their final 81 (38%) to finish 81-81 and in last place (yes, last place; the whole division won between 81 and 90 games).
What were we talking about?  Oh, right.  The Marlins started off 11-1.  Everyone went nuts.  They are 4-13 since.  Haven't heard a whole lot about the Fish lately.

Winners of four straight and 12 of 15, the Brewers come out looking good here.  And that shouldn't come as much of a surprise, as they've more than doubled their "Div%" over the past 2.5 weeks, yet their odds have only gone from +1100 to +975.  They're now just 2.5 games behind the Cardinals, and a half game ahead of Chicago.  It's not the most exciting roster ever, but if Parra starts throwing strikes, Gallardo keeps this up, and Kendall and Hardy get going, they could certainly compete for the division title.

It's almost as if something of note happened shortly before 12:43 PM EST this afternoon:

Just for curiosity's sake -- and this is horribly unscientific, so don't read too much into it -- the difference between those two lines projects to 3.4 wins over 162 games. Which sounds about right.

Because of the enviable position they're in, Manny's 50-game absence won't have a huge effect on LA's playoff chances.  If you figure they're a .552 team with him, and .527 without (which is accurate if he's worth about four wins per 162 games), then they drop from .552 to .543 over the final 133 games of the regular season, and their "Div%" goes from 89% to 86%.  The effect in the Vegas sim is slightly more pronounced, since they were closer to the pack to begin with; in that one, they go from 79% to 74%.  They also have an extra $7.7MM to play with, which can't hurt.
Leave it to ESPN to be completely unreasonable on anyting involving involving PEDs.  The following just scrolled across the bottom line:

"Computer projections adjust Dodgers to win 3 fewer games this season and drops [sic]  their chances of making playoffs from 71 to 66 pct as a result of Manny Ramirez 50-game suspension."

Apparently Manny Ramirez is a 9.72 win player over the course of 162 games. News to me.