Astros' Chances Surge as Cubs, Bucs Prepare for Battle

This post is part of a series about the 2015 MLB Postseason. Follow along here.

Photo credit: Dan Gaken • Creative Commons 2.0

Last night, the Houston Astros defeated the New York Yankees on the road in the second third ever American League Wild Card Game. The Rational Pastime model pegged Houston as slim favorites, despite New York's home field advantage, because of the Astros' superior RPScore. I can't take too much credit for this, since the model only gave Houston a 2% edge over their opponent.

That said, Houston's victory over the 27-time World Series champs may have a profound impact on the rest of the playoffs landscape. Coming into last night's contest, my numbers ranked the Yankees 10th out of 10 playoff squads, whereas they ranked the Astros second (behind only the Toronto Blue Jays). In other words, the results of last night's contest are bad news for the rest of the field.

As a result of last night's victory, the Astros' chances to win it all surged from 7% to 16%, whereas the chances of the rest of the contenders took a slight hit. Four teams suffered a visible change in their chances in the Fall Classic after rounding to the nearest percentage point: the Kansas City Royals (10% to 9%), the Toronto Blue Jays (31% to 29%), the Pittsburgh Pirates (6% to 5%) and the Chicago Cubs (8% to 7%). At the moment, Houston is poised to make a run deep into October.

But if Houston's going all the way, they'll most likely need to surpass the favored Blue Jays, who are still approximate 2:1 favorites to win it all. In fact, nine of the top 10 projected World Series outcomes involve our friends to the north beating some National League franchise. Houston doesn't pop up until the 10th spot, beating the Los Angeles Dodgers in six.

Much like last night, tonight's contest is a toss-up: my model picks the home team Pirates over the Cubs 51% of the time. Also like last night, tonight's results will have a significant impact on the projected odds for the rest of the field. Though the Bucs are lightly favored, the North Siders are a much better squad according to RPScore (a .552 team vs. a .579 team, respectively).

Stay tuned to see how the results of tonight's National League Wild Card Game affect the chances of the rest of the field.