Remaining Strength of Schedules and the Race for Playoff Home Field Advantage

If you go by Baseball-Reference’s Postseason odds, the Astros have a 98.6% chance to win the AL West this year. This figure is actually a lowball assumption, compared to the methods used by 538 (>99%), Baseball Prospectus (99.7%), Fangraphs (99.9%), and MLB.com (100%); those are just the types of odds you get when you have a ten game lead on your division in the last third of the year.

So let’s set our sights a little higher: for instance, what are the chances the Astros finish with the best record in the Majors and secure home field advantage throughout the playoffs? And how likely is it that they’ll improve upon last year’s franchise-best 103-59 record?

As it stands right now, the Astros’ 75-40 record (a .652 winning percentage) is still third in the majors, half a game behind the Yankees’ 75-39 and a full game behind the Dodgers’ 77-40 (both work out to a .658 mark). The Twins are the only other team in the majors with 70 wins or a .600 winning percentage, at 70-44 and .614. Those are really the Astros’ competition at the moment, although the Twins are a pretty big stretch given that they’re fairly far behind and they’d have to leapfrog three different teams to get the title.

There are a few different ways to break this down. If you want to look at how luck has played into the season to get at more of a “true talent” angle, the Astros are actually a step above the Twins and Yankees just by expected won-loss; the Yankees and Twins are at just 70 and 69 wins, respectively, which is more or less in-line with what Minnesota has actually done but a noticeable drop for New York. The Astros have actually been a little lucky themselves by this metric, dropping to “just” 73 wins, while the Dodgers only lose one win and have a clear lead at 76.

Of course, those totals are just based on runs scored and allowed, ignoring things like injuries. Which is something that considerably benefits the Astros and Yankees, given the extensive injuries both have had to contend with. Of course, most of the Astros’ most devastating injuries (Jose Altuve, George Springer, Carlos Correa) are back and seem to be operating at pre-injury levels, which is not really something you can say about New York (at the time of this writing, their team page on Baseball-Reference has a remarkable 18 injuries of note).

And of course, it doesn’t take into account the trade deadline acquisitions, which by far tilt matters into the Astros’ favor. Really, the Yankees and Dodgers were so quiet that Houston could have won this category without the Zack Greinke trade (or with only the Zack Greinke trade, for that matter), with the Twins additions of Sam Dyson and Sergio Romo being the biggest competition. In a race that will very likely come down to just a win or two, the team that added Zack Greinke, Joe Biagini, and a possibly-fixed Aaron Sanchez seems like it has an edge over the teams that added Terrence Gore or Adam Kolarek.

Of course, looking at opposing strength of schedule is another fun way to break this down, since there actually are pretty notable differences here between the teams. Let’s start with the Dodgers, since they have the most radically different remaining schedule:

Dodgers: 45 games remaining, 18 against teams with winning records

The biggest threats here are a three game set in NL East-leading Atlanta (a .586 record), and series in LA against the Yankees and Rays (.569). They also head to Citi Field to face the Mets, who have been on a roll as of late and were the biggest challenger to the Astros’ claim to the title of “most improved at the deadline”. They also have two remaining series each against all of their NL West rivals. The Giants have been hot lately, but still have a losing record overall. The biggest threat there is the Diamondbacks, who only just have a winning record (.504), but have underperformed their expected record by seven games.

At the opposite end of the spectrum, they have one series each against the profoundly-bad Orioles (.333), Marlins (.372), and Blue Jays (.402).

Yankees: 48 games remaining, 25 against teams with winning records

The Yankees basically spend the rest of the year alternating between pretty strong teams and the dregs of the majors right now. They have one series against each of the Indians (.596), A’s (.565), Dodgers, Red Sox (.517), and Rays. But they also still have one series against the Orioles, Tigers (.297), and Mariners (.414), and ten full games against the Blue Jays. The Rangers (.509) have two remaining series against the Yankees as well, and could make things surprisingly rough for the Yankees if they’re still fielding a 25-man roster with only 24 healthy ligaments.

Twins: 48 games remaining, 22 against teams with winning records

There are series against the Nationals (.535) and Brewers (.517), both of whom are in Wild Card position in the NL, and the Red Sox, who have a better run differential than their record implies. There’s a series in Dallas mixed in there as well, but the real thing of note is that they still have ten games against the Indians. There’s a real chance that costs them the division if they don’t take care of business (they’re only 2 games up at the moment), and far more worrisome than any other set of games listed here.

Balancing things out is that the rest of the AL Central is still awful, and the Twins have a lot of games against those teams as well. They still have three full series against the White Sox (.451), and none of those are even in the bottom third of weakest opponents remaining thanks to seven games against the Royals (.357) and ten against the Tigers. If they can handle the Indians decisively, these 26 games against bad teams will give them a lot of opportunities to make up ground on the Yankees, Dodgers, and Astros.

Astros: 47 games remaining, 15 against teams remaining

Two of those fifteen are a homestand versus the Rangers, three are the Rays visiting town, and another two are a road trip to Milwaukee. The remaining eight are all against the A’s. That’s not necessarily a cakewalk, but it seems difficult to argue that one series against Tampa and two against Oakland is a stronger set to square off than any other team’s three hardest remaining series (probably Rays/Yankees/Braves for the Dodgers, Dodgers/Rays/Indians for the Yankees, and Indians/Indians/Indians for the Twins).

And on top of that, while they don’t have a ton of games left to beat up on a specific bad team, like the Yankees and Toronto, or the Twins and the rest of the Central, they make up for that with the widest selection of bad teams. Right now, Houston is en route on a road trip that will match them against the Orioles and White Sox, and they’ll face off against the Tigers and Blue Jays before the month is over. Next month brings two different sets against the Mariners and another against the Royals. And their most common opponent from here on out is the below-average Angels, at ten games.

If you want to break that all down by average record of opponents the rest of the way, the Astros narrowly lose out to the Twins, and both have a decent lead on the Yankees and Dodgers:

The spread isn’t that big in the grand scheme of things (the difference between a .452 winning percentage and a .482 one over 162 games is just a hair under 5 wins), but again, this is a chase that could well come down to just a single game. It’s encouraging that the team closest to them in remaining strength of schedule is the one they already have a sizable lead on, and between this and the improvement they made at the deadline, it feels incredibly fair to call the Astros the favorites to finish with the best record in the majors right now.

And of course, how does all of this compare to the 2018 version of the team? By coincidence, the 103-win 2018 team also had just played their 115^th game of the season on August 7^th last year, and stood two games behind their current pace. That’s a good place for the current team to be!

Despite being ahead of the 2018 team’s pace, though, this version of the team is actually facing a noticeably easier schedule over their final 47 games. The biggest part of that was ten games against a Mariners team that was 65-49 at this point, but there was also a series in Boston against the juggernaut 2018 Red Sox, and the Rockies and Diamondbacks also had records in the .530-.550 range. And most commonalities between this year and last were also better in 2018, from the playoff-bound A’s (.588) to the middling Angels (.496) to the bottom-feeding Blue Jays (.455) and Tigers (.412).

That all added up to an average opponent record of .515 the rest of the way at this point in 2018, which is a much bigger gap than I expected to find. Houston would of course go 30-17, meaning that to break that record yet again, the 2019 ‘Stros can do one game worse overall even while facing the equivalent of a 74-win team rather than an 83.5-win team. Finishing this year with the best record in the Majors feels like it’ll be a close race, and even with the Astros as the favorite, I’m not sure that I’d take them over the field, but finishing ahead of the 2018 Astros feels like an easy prediction to make.