With 30 some odd games left in the regular season, the Cubs and the Angels have solidified themselves as members of the 2008 Postseason. They've done them in different ways, however, which begs the question of, which probable division leader stands a better chance in the playoffs?
Baseball Propsectus has compiled 26 various traits that a team exhibits, and their correlation to playoff success. (Interestingly enough for us Astros fans, W/L record after Aug 31 has the largest negative correlation to post season wins.)
Three traits that have an extremely high correlation to post season success are W/L%, Opponent's BA, and their closer's expected win totals above replacement level. The first two are pretty standard measures, and the last one is basically just a way of figuring out how many wins in a given season has your team's closer added to the aggregate, over what a replacement pitcher (a "AAAA" pitcher, if you will) would have. Francisco Rodriguez's WXRL value is a tremendous 4.562, good for third in baseball. (Source: Baseball Prospecuts). This should come as no surprise, given his high save totals and generally awesome season. While KRod probably hasn't put up the best pure numbers of any closer in baseball, Rivera and Lidge come to mind, he has led the majors in leverage for relief pitchers at 2.19. That 2.19 is staggering- his appearances have come where a run allowed is twice as important as a run allowed in the early innings of a game. Kerry Wood on the other hand, is 30th in the majors with a WXRL of 2.15, and has a leverage score of 1.74. So, not only has KRod out paced Kerry Wood in expected wins, but he has done so in much tighter situations. Round One goes to the boys from Disneyland.
Both teams as a whole have excellent pitching staffs. The Cubs have as good a 1-2 combination as anyone in baseball in Carlos Zambrano and Rich Harden. Their bullpen is solidified with the aforementioned Kerry Wood, as well as Carlos Marmol, Chad Gaudin, Neal Cotts and rookie Jeff Samardija. LA boasts a staff featuring John Lackey, Ervin Santana and suprise stud Joe Saunders. Their own bullpen has experience in the postseason, as Scot Shields, Darren Oliver and MLB save leader Francisco Rodriguez can do quite a bit to ensure that those potent Angel starters do not lose any potential victories. Resumes aside- which teams are better at preventing opposing batters from reaching base via a base hit? The Cubs win out here: .241 to .259. (Source: Yahoo! Sports).
W/L Record is basically a wash, as the Cubs have won one more game on the season. Using this sort of simplistic approach, the Cubs are the better team. I certainly agree, but for more reasons than the ones I just presented. For starters- the Cubs have outscored their opponents by 163 runs, compared to the Angels relatively modest total of 49 runs. The Angels are playing waaayyy above their heads, while lady luck has not been kind to the Cubs this season.
The last reason why I'm so bullish on the Cubs' chances this postseason is their runs allowed this season. Their RA of 523 is not the best in baseball, couple an excellent staff with their terrific offense, and it's pretty apparent that the Cubs are the best team in baseball. While most teams have to decide whether to build their team around offense or defense, the Cubs have the luxury of having a top five offense and pitching staff. What other teams have accomplished this feat as late as August 23rd? In the past five seasons, only the Boston Red Sox of 2007. Whereas other teams need certain areas to over perform (the 2003 Florida Marlin offense, the 2005 Chi Sox bullpen, the 2006 Cardinals team as a whole), the Cubs don't have performances to worry about. The small sample size of playoff series, combined with the fickle nature of BABIP are always worrisome, but judging by the numbers, all the on-field components are in place for a successful playoff run.