Put this all together, and it is easy to see how 2017 appears like it will be the culmination of the Astros’ tear-down and rebuild, along with the fulfillment of Sports Illustrated’s 2014 prediction of them winning the World Series. Beating the Astros seems daunting. Given the Red Sox’s underdog status, it is worth considering how their style of play, namely aggressive baserunning, putting the ball in play, and strong defense particularly in the outfield, matches up against these daunting Astros.

Aggressive Baserunning

The Red Sox ran wild on the basepaths this year. A few weeks ago I expressed my concerns with their approach to baserunning, and not much has changed since. They attempted 137 stolen bases this year, seventh most in baseball. They took an extra base 43 percent of the time, tied for the third highest rate in baseball. They advanced on fly balls, passed balls and wild pitches 175 times, which was tied for the fourth most in baseball. Trying to take an extra base is of course a worthy effort, but there are costs, which is where my concerns entered the frame. Red Sox batters’ aggression on the bases resulted in 118 baserunning outs (81 Outs on the Bases [OOB], 31 caught stealing, six pickoffs). That total was the third-highest in baseball this year. By now I am sure you get the point: they tried to push bags and made a lot of outs doing so, ultimately leading to below average results (-3.5 BRR). The Astros were similarly aggressive on the bases, but I will leave that for now, and instead focus on how Houston fared in limiting opponents base running efforts.

The most obvious place to start is with the Astros’ control of the base stealing game. By the simplest measure, stolen base percentage, the Astros were miserable at holding runners. Their 88 SB%-allowed (116 attempts) was the worst in baseball and six percentage points ahead of the second worst White Sox. BP’s advanced catching metrics include Swipe Rate Above Average (SRAA), which attempts to account for things like pitchers’ times to the plate and quality of baserunners. By SRAA, among catchers with at least 2,000 pitches received, Evan Gattis and Brian McCann (Houston’s two primary catchers) were third and fifth worst. With this in mind, Red Sox runners should feel comfortable trying to steal a base, and this goes especially for late game pinch runners like Rajai Davis.

Stealing bases, while the most salient part of a team’s baserunning, is only one part. Advancing extra bases on balls to the outfield is another critical part. An example of just how important tagging up on a flyball can be happened in Game 7 of last year’s World Series. As noted, the Red Sox have been aggressive in trying to take extra bases, but against the Astros they should take greater caution. The Astros feature outfielders with strong arms. By both Fangraph’s ARM measure and Baseball Reference’s Total Zone Outfield Arm Runs Above Average, the Astros outfielders have the best group of arms among the teams remaining. George Springer, Josh Reddick, Derek Fisher, and Marwin Gonzalez each rated above average. I know Brian Butterfield wants the team to move away from being a station-to-station team, but giving up outs is not an ideal way to do so. I am interested in seeing if the Red Sox tone things down a bit in this series.

Making Contact

The Red Sox finished the season among the league leaders in Contact percentage, trailing only Houston and Cleveland for top spot. Much has been made about the Red Sox’s inability to hit home runs, or their general lack of power. Instead they were a group that strung hits and walks together to score runs and had strong plate appearances against the power pitchers of the league. The good news is that most of the Astros’ rotation includes pitchers who would be classified as power pitchers, at least by Baseball-Reference’s split definition. These are the types of pitchers against whom the Red Sox have fared well, relative to the rest of the league. In accordance with the power pitcher label, Astros hurlers tend to strike a lot of guys out – they finished third in baseball in strikeout rate – but as you know the Red Sox do not strike out very often. Something is going to give here.

We know that when the Red Sox put the ball in play it tends to stay in the yard. Putting the ball in play means the Houston defense will be tested and they were not exactly a strong group on defense:

Note: UZR is not available for catchers and I was not sure about how to combine Gonzalez’s infielding (generally bad) and outfielding (generally good) numbers.

The differences across metrics are difficult to reconcile, and because these numbers are based on a single season of data we are dealing with wide confidence intervals, but you can see this group lacked something on the defensive side of the game. Ideally the Red Sox’s put-it-in-play approach can take advantage of this.

Defense

While we lauded Red Sox batter’s ability to avoid strikeouts, the Astros were even better; two full percentage points better. They hit home runs, hit for power, and they run. Simply put, the Astros’ offense is excellent. This means the Red Sox’s defense will need to be on point. There were times this season when the Red Sox struggled defensively and it lead to frustrating games. However, in the end they finished as a top three defensive group by DRS and UZR. Here is a table for Red Sox’s defenders similar to the one I gave above for the Astros:

Mookie’s numbers are just silly. BP sees Jackie Bradley’s defense as below average, which is surprising, but otherwise things are in line with what I expected and you can see this was a strong defensive group. They can go and get it, which should help tamp down the Astros lineup that puts the ball in play, and give Red Sox pitchers confidence that they can attack within the strike zone.

All told, it seems like the Red Sox’s style of aggressive baserunning, hitting for contact, and playing strong defense line up well against this Astros team. That is not a startling revelation, as for the most part those things line-up well against any team and that is why the Red Sox won their division. Nevertheless, I understand how the Red Sox come into the series as the underdog. The Astros are an excellent baseball team. But the Red Sox are at least a really good one, and the differences between these teams are not that large in a best-of-five series. Especially when the Red Sox can send Chris Sale to the mound for two of the five games (if necessary). On his own, Sale is as important as any other factor on this Red Sox team this postseason. Getting a solid outing from him tonight and taking Game 1 is critical for the Red Sox’s chances of winning the series. I will certainly be watching the aspects of the Red Sox’s style I outlined above, but mostly I’m just excited for the series to be underway.

Photo by Bob DeChiara – USA TODAY Sports

As you can see, on-base percentage is also down this year from last year, but not to the extent of slugging, which is down almost 50 points. The drop is not just the lack of David Ortiz. With the exception of the catchers, each of the everyday guys is slugging at a lower rate than they did last year.

The decline in slugging this year is interesting on its own, but the (possible) downstream effect of increasing aggressiveness on the bases makes it even more interesting. This year the Red Sox are one of the most aggressive teams on the bases. They have attempted 112 stolen bases (nabbing 85 of them), sixth-most in baseball. They have taken an extra base (i.e., advanced two bases on a single, three bases on a double) 42 percent of the time, also sixth-highest in baseball. They have advanced on fly balls, passed balls, and wild pitches 152 times, second-most in baseball. They are undoubtedly making an effort to push bags, but it has not come without a cost. In addition to those positive baserunning items, Baseball Reference tracks Outs On Bases (OOB) and the Red Sox are on the wrong end of it. They have already made 69 OOB, easily the highest amount in baseball. Add in the 27 times they were caught stealing and the six times they have been picked off, and you have over one hundred guys on base turned into outs. Compare these to last year and you find:

Keep in mind the 2017 Red Sox still have a month to play, but have already surpassed last year’s squad in all but extra-base taken percentage (XBT%) and pickoffs. I did not recall noticing how often the Red Sox were picked off last year. In any case, those numbers are remarkable. And, according to Brian Butterfield, the coach leading the charge of aggressiveness on the bases, it is all part of a plan to adapt from being a team that is station-to-station and relies on hitting the ball into the seats.

I understand the sentiment and the desire to be a multi-faceted offense that puts pressure on the defense and manufactures runs. What’s more is that when you are a lower scoring team, these sorts of tactics make more sense than when you are high-scoring outfit. While outs are always precious, for groups that struggle to score, each out has less run-purchasing power, so to speak. As evidence of this, take an overly simplified example using run expectancy. In 2015, a low-scoring run environment (4.31 R/G), the cost (in run expectancy, RE) of a runner getting caught stealing second with no outs and nobody else on base was 0.586 runs. Contrast that with 2004, a high run scoring environment (4.88 R/G), where it was 0.634 runs. Not coincidentally, the difference in league-wide run scoring between 2015 and 2004 (0.57 R/G) is close to the difference between the 2017 and 2016 Red Sox teams (0.54 R/G), so the example is relevant. It means that the extra outs on the bases made by this year’s team (relative to last year’s group) could end up costing the same amount in terms of run expectancy. Making an out is costly, it is just slightly less so for a team that tends to score less (perhaps because they don’t sock dingers). So there is some logic behind the plan to implement greater aggression on the bases with this low-slugging 2017 squad. But, while that sounds nice, they aren’t even doing it well compared to last year: By Baseball Prospectus’ Baserunning Runs, the high scoring 2016 Red Sox were basically average on the bases (0.6 BRR) and this 2017 group is considerably below average (-6.9 BRR).

Stealing bases and taking the extra bag as often as possible can help run scoring and is fun to watch as a fan, but doing so won’t turn a pumpkin into a stagecoach.

There is a notion that things like baserunning, hitting for contact, and small ball strategies become stronger assets in the playoffs. After all, the temperature drops and the quality of pitching increases, so big bopping offenses will be neutralized, right? Butterfield suggests as much in his explanation for encouraging the team to run wild. But the reality is that there isn’t good evidence to support this as true. Rather, it is the teams that hit the ball out of the yard that tend to succeed in October. As Joe Sheehan enjoys saying: Ball go far, team go far. Even those plucky 2014 and 2015 Kansas City Royals teams who changed baseball forever with their contact-prowess and aggressive running, actually did a lot of their playoff winning by (uncharacteristically) hitting a bunch of home runs. Nevertheless, Eric Hosmer’s dash home and Lucas Duda misfiring a throw is what gets remembered.

Relying on baserunning is a really difficult way to make an offense go. Stealing bases and taking the extra bag as often as possible can help run scoring and is fun to watch as a fan, but doing so won’t turn a pumpkin into a stagecoach. Getting guys on base frequently and then moving those guys around with hits (even the ones that go over the fence) are the critical elements in a good offense. Doing either of those things at a low rate makes it hard to score, as it has been for the Red Sox this season. Butter’s plan might sound good and even have some run expectancy logic behind it, but ultimately it won’t be enough to carry this team through October.