A Glance at Rest-of-Season Strength of Schedule

Welcome to the time of year where it’s all about fractions. If the regular season were a game, we’d be at the start of the sixth inning, and the leverage is beginning to climb, making everything more important. Your team’s in the race and you want it to make a trade. Maybe the deal projects to add half a WAR over the course of the remainder. What’s the value of a win on the free-agent market, $7 million? And wins are more valuable in high-leverage positions on the win curve, right? A half-WAR improvement might be worth five or ten million dollars. That’s a lot of dollars! For many of the teams in baseball now, runs are more important than they would’ve been in April.

People care now about every last little detail. You never know which detail might end up determining which teams do and don’t make the playoffs. Among the details to care about: strength of schedule. Schedules, as everyone knows, are unbalanced. So some teams might have easier schedules than others. Now that we’re at the All-Star break, who’s looking at a schedule advantage, and who’s looking at a schedule disadvantage? Not a single race has been decided, so opponent identity will be some kind of factor in how the rest of the season plays out.

When I looked at this before the start of the season, I figured out average projected WAR for each team’s scheduled opponents. This time I’m taking a slightly different approach, made possible by some of the pages we have here on FanGraphs. At the core, these numbers still depend on the rest-of-season projections. Maybe you’ve been to this page. You’ve almost certainly been to this page. Both of them include rest-of-season projections, but you might notice that the numbers don’t perfectly match up. For example, on the former page, the Dodgers are projected for a .555 rest-of-season winning percentage, but on the latter, that same number is .553.

There’s a reason for this! That reason isn’t a glitch. The former numbers are based on projected talent. The latter numbers include adjustments, like adjustments for opponents, and adjustments for home games and away games. So this actually makes things very simple: we can figure out schedule strength by finding the difference between the projections on the two pages. A team projected for more success on the second page is considered to have an easier schedule than a team projected for more success on the first page.

Obviously, these numbers are only as good as the projections. Obviously, there’s going to be player movement in the weeks ahead, and some teams will be weakened and strengthened. The Cubs are weaker now than they were a short while ago. The Rays, probably, will be weaker in August than they are today. But let’s accept the error bars and move on to the chart. On the y axis will be wins. The calculation: adjusted projected win total minus unadjusted projected win total. So this measures schedule-based win advantage or win disadvantage over the final 2.5 months.

I should’ve warned you to prepare to be underwhelmed. There are differences evident in the chart, but look at that y axis: the biggest positive is 1.1, and the biggest negative is -1.1. In black and on the left, incidentally, is the American League; in red and on the right, the National League. All but one team have fewer than 70 games remaining, and while schedule strength is a factor, it’s not nearly the same kind of factor as, say, own roster strength. The absolute biggest takeaway point here is that strength-of-schedule is a pretty small factor. It’s not worth being up in arms about.

But still, differences are differences. You see mostly good teams with positive numbers, and weak teams with negative numbers. This is because good teams have the advantage of not having to play against themselves, while weak teams have the identical disadvantage. The Tigers don’t have to deal with a few series against the Tigers. The Phillies don’t get to feast on a few series against the Phillies. That’s just part of how things have to be, and I’ll note here that the projections continue to love the Nationals. And yet, there’s a team in the NL with an even bigger advantage than the Nationals.

That’s the Cardinals, who’re in a delicate place. They’re one back of the Brewers in the NL Central, and they’re a half-game back of the Wild Card. If you believe the information presented here, the Cardinals have the NL’s most friendly schedule the rest of the way. The difference between them and the Brewers here is a full win, which isn’t insignificant given the state of things. You might also notice the Braves’ position; on the unadjusted page, they finish with a .525 winning percentage, but on the adjusted page, that’s .517. You can see why the numbers so vastly prefer the Nationals as NL East champions.

On the AL side, you see some teams involved in the Wild Card hunt. Arguably the two best teams have the two most favorable schedules, but then you have the Indians, Royals, and Blue Jays, with the Yankees bringing up the rear. The Wild Card is basically always going to be an incredibly close race, so single games really can make a huge difference, and the Indians might have relatively smoother sailing than, say, the second-slot-leading Mariners. We can at least say strength-of-schedule isn’t not a factor.

So many elements are going to combine to make a difference over the final several weeks. Relative schedule strength is going to be one of them. It’s not going to be as important as it might seem — schedules, generally, just aren’t very lopsided, especially within leagues — but every run counts, right? It’s something to chew on here as baseball takes a break.