Strength of Schedule and the Pennant Races
No team plays a completely balanced scheduled over the course of a season. Some divisions, naturally, are better than others. Because intradivisional games account for roughly 40% of the league schedule, there is necessarily some irregularity in the strength of competition from club to club. Interleague play, which represents another 10% of games, also contributes to this imbalance. Given the sheer numbers of games in a major-league campaign, the effect of scheduling ultimately isn’t a major difference-maker. Talent and luck have much more influence over a club’s win-loss record. In any given month, however, scheduling imbalances can become much more pronounced.
Consider this: at the beginning of the season, just one team featured a projected gain or loss as large as three wins due to scheduling. The Texas Rangers were expected to lose three more games than their talent would otherwise dictate. Right now, however, there are eight teams with bigger prorated schedule swings than the one the Rangers saw at the beginning of the season — and those swings could have a big impact on the remaining pennant races.
To provide some backdrop, the chart below ranks the league’s schedules, toughest to easiest, compared to an even .500 schedule.
The Diamondbacks have a pretty rough go of it. Outside of five games against the Padres, the other “worst” team they play is the San Francisco Giants. They have one series each against the division-leading Astros, Braves, and Cubs along with a pair of series against both the Dodgers and Rockies. If Arizona were chasing these teams for the division or Wild Card, their schedule would present them with a good opportunity for making up ground. Given their current status, however, it just means a lot of tough games down the stretch.