When you look up and see that the Athletics are in the midst of a two-game mid-week series against the Marlins in late May, you might suspect that the major-league baseball schedule is simply an exercise in randomness. At this point in the campaign, that’s actually sort of the case. The combination of interleague play and the random vagaries of an early-season schedule conspire to mean that your favorite team hasn’t had the same schedule as your least favorite team. Let’s try to put a number on that disparity.

Over at Baseball Prospectus, they have a statistic called oppRPA+. That’s a mouthful, but it’s not as if xwOBA — which is also quite useful — rolls off the tongue like an entry from the lover’s lexicon, either. Here’s an explanation real quickly.

RPA+ is computed as: RPA/lgRPA Where lgRPA is the league runs per plate appearance, adjusted to match a player’s run environment (adjusted for park, in other words). The scale of RPA+ should correspond with that of OPS+ and similar metrics; it will produce the same rank order as True Average, however.

In other words, oppRPA+ is a park-adjusted number that captures the strength of the opponent by looking at their results to date. By putting their pitchers and hitters on the same scale (usually a higher oppRPA+ means worse pitchers) and then weighting oppRPA+ by batters faced and plate appearances and then grouping by team, I’ve created a strength of schedule number for each team.

A higher number means that the opposing hitting and pitching that these teams saw was, on average, better than the league average.

Strength of Schedule to Date Team Opp. Pitchers Opp. Batters Strength of Schedule PIT 104.9 106.2 105.6 SFN 102.6 107.8 105.2 KCA 102.2 105.8 104.0 TOR 99.7 107.6 103.7 DET 105.3 100.4 102.9 SDN 100.7 104.7 102.7 CLE 105.1 100.3 102.7 PHI 99.5 105.4 102.4 TBA 99.7 104.9 102.3 HOU 103.8 99.5 101.6 BAL 94.4 108.2 101.3 NYA 96.9 105.6 101.2 ANA 101.2 101.1 101.1 CHN 96.4 105.8 101.1 TEX 100.7 98.9 99.8 BOS 94.1 104.7 99.4 SEA 99.4 98.3 98.9 CHA 98.4 99.3 98.8 COL 94.0 103.6 98.8 OAK 100.5 96.8 98.7 MIN 101.2 96.0 98.6 MIL 92.0 104.3 98.2 SLN 93.4 101.4 97.4 MIA 93.2 101.0 97.1 NYN 88.8 103.6 96.2 CIN 90.9 101.0 96.0 WAS 92.4 99.0 95.7 ATL 92.6 98.3 95.4 LAN 92.7 96.4 94.6 ARI 93.6 95.3 94.5 SOURCE: Baseball Prospectus Based on oppRPA+.

Higher number means tougher opposition.

As of now, the Pirates only have a 7% chance of making the playoffs, but before selling, they may want to look at the schedule and see if their fortunes will change. There’s been a decent amount of interdivision play early in the year. The club has also faced the Cubs six times. Now the Pirates only have 13 more games against Chicago — and the lack of teams from the NL Central at the top of this list could mean hope for the Bucs. Tyler Glasnow has two good games in his last three, Jameson Taillon is throwing bullpens, and the Pirates have seen the toughest schedule in baseball.

The Giants find themselves in a similar position: a team that has recently been good but has also experienced enough struggle this year to begin having to weigh selling versus holding. I’ll admit I was skeptical when Dave Cameron recently cautioned the Giants from selling too early, but his point that the league is gathering in the middle was well taken. And then there’s this fact: the Giants have seen some tough teams in the early going. Seventeen games against the Dodgers and resurgent D-backs might do that to you.

You get to a more mixed bag when you try to use this to look at Toronto. Twelve teams have seen tougher pitchers than the Blue Jays, and yet the Blue Jays are 12th in the American League in runs scored. They’ve had some mitigating circumstances with Josh Donaldson and Troy Tulowitzki out, but the data here isn’t necessarily encouraging for their offense.

On the other end of the spectrum, the Mets might highlight a potential flaw in the analysis. The team from Queens looks like it has seen tough opposing batters! But this is based on their opponents’ own results. What if the weakness of their own pitching has given their opponents good results stats? Stats which make their opponents seem more difficult to play? That would really be a comment on the quality of their own pitching, no? The Mets have the worst team ERA in the National League right now. They could be making their opponents look better than they are.

Still, when Dave Cameron took a look at the D-backs and what they’ll do the rest of this year, he mentioned the strength of schedule, and pointed out how many games Arizona has had against the Padres. He was right to do so, as it looks like the D-backs have had the easiest schedule in baseball so far. It’s a little different, though, to have had success in the easy portion of the schedule, as the D-backs have, then to be the Braves and scuffling through what looks like an easy schedule so far.

That might be the best lesson here. If you’re struggling and the schedule has been easy, maybe you’re that much closer to selling. If you’re doing well and the schedule has been hard, maybe you’re that much closer to buying. But if you’re the Reds or the Padres, how much do you really care about how hard the schedule has been so far? You’re in the early steps of a plan, and a few months this year shouldn’t move the needle that much.