The longer the Rockies continue to sit at the top of the National League West, the more you are likely going to hear about the team’s run differential. The Rockies have continued to outperform their run differential, and, so we’re told, this means they really aren’t that good. As so often happens, it’s a bit more complicated than that.
Here’s the thing about the Rockies’ run differential: it’s just okay. Heading into Friday’s games, the Rockies run differential sits at plus-12. By way of comparison, that is the same as Cleveland and one less than Baltimore. Cleveland, currently 18-15, entered the season as one of the consensus best teams in baseball. Then there’s Baltimore (22-11), who the most optimistic prognosticators predicted to finish the season below .500. The Rockies, by way of reminder, sit at 23-14, a 103-win pace (same as when Eric Garcia McKinley looked at the numbers last month).
Run differential leads us to Bill James’ “Pythagorean theorem”. Pythagorean record cuts through the results and uses a team’s runs scored and runs allowed to see how many games a team “should” have won. Based on this, the Rockies record “should” be 19-17, an 86-win pace. Going back to our compatriots, Cleveland would be 18-15 (their actual record) and Baltimore would be 18-15, a four win difference.
How the Rockies have overperformed their Pythagorean record is a different story, but, for our purposes, it’s important to remember the Rockies have banked those wins and don’t have to give them back. But going forward, it’s a little disconcerting they have outperformed their Pythagorean record by four games.
But there are reasons to be encouraged, by way of higher order win percentage. Clay Davenport explains the methodology more thoroughly here, but for those who don’t care to click on yet another link, third order win percentage (from Baseball Prospectus) and BaseRuns record (from FanGraphs), look at all the offense a team has produced (hits, walks, stolen bases, et al) as well as the quality of opponent to tell us how many runs a team would normally get (and allow).
Snap back to reality: what does this mean for the Rockies in 2017? The Rockies’ record by third order win percentage is 21-15, a 93 win pace and exactly halfway between their actual record and their Pythagorean record. BaseRuns has them at a slightly worse 20-16, or an 87 win pace.
To understand the difference this makes, consider again Cleveland and Baltimore. Both systems have AL favorite Cleveland at 19-14, while Baltimore sits at 17-15 by third order win percentage, and a disheartening 16-17 by BaseRuns. In other words, Cleveland is sitting right where they should be and were expected to be; Baltimore is tempting fate (once again). The Rockies, by comparison, might actually be a good team, despite naysayers who are quick to label them pretenders.
This is all about what the team has done, not about what they will do. For that, we turn back to Baseball Prospectus and FanGraphs for their respective playoff odds reports. While both sites project the Rockies to be slightly worse than a .500 team the rest of the season, that would still be enough to get them to 85 wins. In a weakened National League Wild Card race, that is good news. Baseball Prospectus has their playoff odds at 54.6 percent, fourth highest in the league, and FanGraphs sets it a 49.9 percent, fifth highest in the league.
That’s right: the Rockies are just as likely to make the playoffs as miss them. Next time someone tries to bring the run differential argument, point to the figures that suggest otherwise.