The Astros Effect on the AL Playoff Race

The Houston Astros are coming to the American League West. The Houston Astros current Major League roster looks like one of the worst we’ve seen in recent memory, as the team is currently in the midst of a total organizational overhaul. The Astros are almost certainly going to be one of the worst teams in baseball this year, and their addition to the AL West means that the schedules for Texas, Anaheim, Oakland, and Seattle will be easier this year than they were last year.

Just how much will playing one of the league’s worst teams 19 times help the AL West contenders? Well, first off, we need to know where those games are going to come from.

Let’s use the Angels as an example of the scheduling adjustments that have been made to make 19 games against the Astros work. MLB wanted to preserve the same number of intra-division match-ups, so the Angels are still going to play the Rangers, Mariners, and A’s a combined 57 times, just as they did a year ago. To add 19 match-ups against Houston, the league had to trim a portion of the games against teams from other divisions. The count of where those cuts were made to create 19 additional games against their new divisional rival:

Team 2013 2012 Difference
Detroit 6 10 4
Tampa Bay 7 10 3
Minnesota 6 9 3
Cleveland 6 9 3
Baltimore 7 9 2
New York 7 9 2
Kansas City 7 9 2
Toronto 7 8 1
Chicago 7 8 1
Interleague 20 18 -2

The Angels will now play 21 fewer games against the AL Central and AL East, with the extra two games that were cut from those teams going to additional interleague match-ups. Here, you can see how it’s not just playing a poor Houston team that could be a potential boon to the Angels, but it’s dumping a decent chunk of their games against some of their toughest AL competition. Last year, the Angels played 29 games against Detroit, Tampa Bay and New York, going 10-19 in the process. This year, they will play just 20 games against those three teams.

But, of course, this isn’t just a single sided coin. In addition to getting fewer games against the Tigers, Yankees, and Rays, they also lose a series against Minnesota, who might challenge the Astros in the race for the #1 pick in the 2014 draft, and lose some games against the mid-to-lower-tier AL clubs as well. Clearly, though, the games being shifted to match-ups with the Astros are coming from a group of games that were against much stiffer competition previously.

To take this a step further, we can make an educated guess as to just how many additional wins we might expect the Angels (and the Rangers, Mariners, and A’s) to get from this new schedule compared to what they might have been expected to win under the old format. The Astros won 34% of their games last year, and that was with some decent performances from since-traded players such as Jed Lowrie, Wandy Rodriguez, and Wilton Lopez. Even with some improvement from a few young players and some carryovers, it’s hard to see the Astros being a significantly improved team in 2013. If we project a slight improvement — it’s really hard to lose 107 games, even when you’re rebuilding — we might generously call them a 60 win team in 2013, which means that they would be expected to win 37% of their games next year.

However, because we believe that the Angels are a better than average team, the Astros shouldn’t win 37% of their match-ups against Anaheim. By using a neat little mathematical tool developed by Bill James called log5, we can estimate the outcome of those 19 Angels-Astros match-ups, however. If we assume that the Angels have the talent level of a 90 win team — that is, they would win 55.5% of their games — then we’d expect the Angels to beat the Astros in 68% of their head to head match-ups, which translates to a 13-6 expected record in those games.

How would they have done under the old system? Well, if we look at the overall strength of the competition that they are playing fewer games against, we note that they are skewed towards above average teams, mainly thanks to the reduction in games against Detroit, Tampa Bay, and New York. Overall, the same methodology would have expected the Angels to go just 10-9 under the old schedule, so playing the Astros is a three win bump for Anaheim.

The math is essentially the same for each of the other three AL West incumbents, even teams with less imposing rosters like Seattle. While the Mariners might not win as many games against the Astros as the Angels, Rangers, and A’s, they’ll still get the benefit of losing fewer games against the AL East squads, and so the relative benefit comes out to three additional wins for them as well.

Three wins probably won’t be enough to push the Mariners into the playoff race, but it could very well be a decisive margin in determining the American League Wild Card teams. For Texas, Anaheim, and Oakland, the arrival of the Astros might give them enough of a cushion to sneak out a wild card berth, even if their rosters might not stack up against Toronto or Tampa Bay on paper. Thanks to the unbalanced schedule, it’s not always about being the best team, but simply being the team that takes the most advantage of inferior opponents.