Coming into the AL West showdown in the ALDS, the Houston Astros and Oakland A’s were fairly even teams, both statistically and on paper. Because of this, a closely played series that would need a deciding fifth game seemed to make the most sense. As it turned out, no fifth game was necessary, and the series itself wasn’t exactly a tightly contested one. The Astros’ offense obliterated the reputable Oakland pitching staff. Let’s examine how that came to be.

A Balanced Attack

The Astros outscored the A’s 33-22 in their 3-1 series victory. Just by watching each game, the Astros’ winning formula was easy to figure out: they hit bombs. But then, so did the A’s. The two teams sent so many balls out of the park that they broke the playoff record for total home runs hit in a Division Series. Each team hit the same number of homers (12).

Aside from the power output though, the Astros did something that the A’s did not: they got on base a lot. This is one of the great separators of the series, and a key reason why the Astros scored 11 more runs. How did the Astros achieve this? Not in the way you’d initially think.

The regular season OBP was .312. The OBP in the ALDS? .388. But the dramatic increase did not stem from increased walks. The team’s ALDS walk rate was 7.3%, a tick below their regular season rate of 8.6%. The sizable jump in OBP is thanks to a .322 batting average in the ALDS.

From that, it’s easy to assume the Astros simply swung the bat more often. They did not.

Focus and Precision

During the regular season, the Astros’ swing percentage was 46.3%. Against the A’s, it dropped sharply to 31.4%. Subsequently, the team’s chase rate also fell. In the regular season, it was 27%. In the ALDS, it was 18.6%, a massive improvement. Additionally, the Astros’ whiff rate was just 15.6%, which was also markedly better than their already league-leading 22.3% figure in the regular season.

The Astros did their damage by staying in the zone and absolutely punishing the A’s when they threw strikes. There’s one part of the zone that I’d like to highlight using a handful of metrics.

During the regular season, this is how the Astros performed against middle-middle pitches:

Those numbers look great at first glance, but when compared to other teams, they’re mediocre at best.

Here’s how the Astros did in the ALDS:

The spike is substantial across the board. It is elite production against middle-middle pitches. Small sample size aside, when the A’s made a mistake over the heart of the plate, they paid for it.

Something else that’s worth mentioning is how the Astros fared in 2-strike counts. Using the same metrics as above, here’s how they did during the regular season:

And in the ALDS:

In seemingly every way, the Astros’ lineup was significantly revamped against the A’s. Oakland boasted perhaps the best bullpen in baseball, and yet they finished the series with a 6.27 ERA. While their rotation utterly failed them this series, a 6.27 ERA is astounding, considering how deep a unit they were projected to be.

Summation

Juiced balls or not, the Astros and A’s played on equal terms at a neutral field. The A’s were supposed to make a deep playoff run by riding their bullpen. That was going to be a challenge with there are no days off during the postseason series (except for the World Series), but that was to be expected. What wasn’t expected was an Astros lineup inadvertently playing possum in the regular season, only to explode in the playoffs against a strong pitching staff.

So far, the Astros are following the mold of the 2018 Boston Red Sox: a lineup that is unyielding with a contributory pitching staff.

It’s apparent that the Astros’ hitters are playing with supreme confidence again. They’re going to need it in the ALCS. Top to bottom, the Tampa Bay Rays may have the finest pitching staff in baseball.

The data in this article was compiled via Baseball Savant