Astros' road dominance puts them in rare air

August 17th, 2018

The Astros struggled on their most recent homestand, losing the first five games to the Mariners and Rockies before recovering to blow out Colorado, 12-1, in Wednesday's finale.
That slide, coupled with Oakland's recent surge, sliced Houston's American League West lead down to two games. But perhaps fortunately for the defending World Series champions, they begin a nine-game West Coast road trip on Friday night at Oakland.
Typically, a long road trip would be cause for consternation, not celebration. The 2018 Astros have not been typical, however. Instead, they have put themselves on track to becoming one of the best road teams in baseball history.
Houston is an unremarkable 33-29 (.532) at home and a quite remarkable 41-18 (.695) away from Minute Maid Park. Three games against the red-hot A's -- followed by three apiece at the Mariners and Angels -- will put that success to the test. For now, at least, the club is in rare territory.
That .695 winning percentage currently ranks as the 10th-best road mark in a season since 1901. Yet many of the teams that have fared better did so in a much different environment, before the game was integrated and expanded, and the schedule was lengthened.
Here, though, are the best road winning percentages since the Expansion Era began in 1961:
1. 2001 Mariners: 59-22 (.728)
2. 2018 Astros: 41-18 (.695)
3. 1971 Athletics: 55-25 (.688)
4. 1972 Reds: 53-25 (.679)
5-T. 1994 Expos: 42-20 (.677)
5-T. 2018 Red Sox: 44-21 (.677)
Included in that 41-18 record is a 6-2 mark on the team's most recent road trip against the Mariners, Dodgers and Giants, and a 10-0 sweep at Texas, Oakland and Kansas City in June. The latter made them just the seventh team since 1953 to go unbeaten on a voyage of at least 10 games.

Entering Friday, the Astros trail only the 2001 Mariners in the 58-season stretch since 1961. Meanwhile, this year's Red Sox are only three games behind the Astros' pace as they also try to chase down the '01 Mariners' record-tying mark of 116 total victories. Look at it a little deeper, however, and the Astros stand out even more for their dominance, which includes eight victories by eight runs or more -- five against postseason contenders.
The 2018 Red Sox have a run differential of plus-99 on the road, which is great. The Astros have a run differential of plus-155, which is historic. With 22 road games remaining, it already ranks ninth going back to 1901, although the '39 Yankees (a mind-boggling plus-290) are uncatchable.
Here are the best run differentials on the road in the Expansion Era (since 1961):
1. 2018 Astros: +155 (324 scored, 169 allowed)
2-T. 1998 Yankees: +151 (493 scored, 342 allowed)
2-T. 2002 Red Sox: +151 (463 scored, 312 allowed)
4. 1998 Braves: +144 (423 scored, 279 allowed)
5-T. 2001 Mariners: +137 (487 scored, 350 allowed)
5-T. 1997 Yankees: +137 (492 scored, 355 allowed)
That run differential -- more than a 100 runs better than Houston's mark at home -- yields an expected winning percentage of .767. In other words, for as good as the Astros have been away from home, their run differential suggests that they should have an even better record.
Should-haves aside, how are the Astros doing this? Unsurprisingly, they are flourishing on both sides of the ball.
Outside of Minute Maid Park, Houston is scoring 5.5 runs per game with a .792 OPS, and the club's 116 weighted runs created-plus (wRC+) ranks second in the Majors to Oakland's 118.
The pitching may stand out even more. The Astros are allowing less than three runs per game, with a 2.70 ERA that is the lowest for any club on the road since the 1972 Orioles posted a 2.67 ERA behind the likes of Hall of Famer Jim Palmer. Houston's 10.3 strikeouts per nine innings on the road would break the single-season record set by ... last year's Astros.
Opposing batters, with the benefit of playing in their home ballparks, have posted just a .209/.282/.328 line against Astros pitchers this season. Their .609 OPS is roughly what Cleveland's or Houston's own have surrendered for the season.

It's also the lowest road OPS allowed by a team since that same '72 Orioles club limited opponents to a .607 mark. Since 2000, the closest road performance by a pitching staff belongs to the '15 Indians (.644 OPS).
None of this guarantees that the Astros will continue to dominate on the road and leave their performance at Minute Maid Park in the dust. The 2017 Astros also performed better away (.654) than at home (.593), not to mention winning Game 7 of the World Series at Dodger Stadium. But the '16 club was slightly better in Houston, and the '15 version that made the postseason shined at home (.654), while struggling on the road (.407).
These things can fluctuate, and there isn't necessarily some secret sauce that makes the Astros excel on the road. But with the standings tightening and Oakland waiting, the defending champs will hope that their away game magic continues.