Is this the worst collapse in Arizona Diamondbacks history?

On Thursday, August 30, the D-backs beat the Dodgers 3-1 in Los Angeles behind Robbie Ray, improving their record to 74-60. They were 1.5 games ahead of the Rockies in the NL West. The following night, they were seven outs away from extending the division lead to two games. Then, Zack Greinke gave up a game-tying home-run to Enrique Hernandez, and the following inning, a go-ahead shot to Justin Turner. Arizona lost that night, dropped each of the next two games by a single run to fall out of first place, and after last night’s defeat to Chicago are 4-14 since August 30. They can’t even claim to have been unlucky, having been outscored by 38 runs over that time.

While Game #134 is an entirely arbitrary endpoint, there’s a case to be made that, unless we improve significantly, this will be the biggest slump of overall team performance in Diamondbacks history. Generally, how a team does over the first 134 games is a good indicator of how they will perform over the final 28 in the schedule. I dug through the history books for the D-backs, and during the first two decades of play, from 1998-2017, their W% in games #1-134 was .494, compared to .488 over games #135-162, a change of only six points. The biggest gap was probably understandable: an improvement of 163 points in Arizona’s inaugural season, going from .373 to .536. But as often as not, the difference has been less than 55 points.

Then there’s this year. After a win percentage of .552, the D-backs have slumped to that 4-14 record mentioned, a W% of only .222, which is three hundred and thirty points worse. It’s a gap more than twice as big as the biggest previous difference, which is almost certain to be surpassed. [If they want to avoid setting a new record for difference in W% before and after Game #134, they need to go 7-3 the rest of the way. The resulting 11-17 record would give them a .393 W%, a drop of “only” 159 points.] The chart below shows how the team’s record compares each season since 1998, and to the current point this year. Blue areas indicate the D-backs were better early, red that they were better late.

You can see, not only has this been the biggest drop-off, it’s on pace to be easily the worst record over the final 28 games, regardless of previous performance. Hell, even in 2004, the D-backs went 9-19 - the 2018 team would need to play .500 ball the rest of the way to match that record. In 2014, Arizona did go 8-20, and expanding the zone a bit, that was part of a streak where they won only eleven of their last forty games. This season’s model has already matched that, with ten left to play. But that 2014 team never got above .500, and was sixteen below at the break, so this was much more of a drop from poor to bad, rather than from contention to being so terrible, I’ve all but stopped watching.

I should say, the current 4-14 streak isn’t particularly unusual. Heck, the D-backs already did worse this year, going 3-15 from the 8th-27th May. But I wonder just how badly things might end up being over these final 28 games. Arizona hasn’t been worse than 7-21 over ANY such stretch since 2004, most recently getting seven wins from June 29-August 3, 2016. They’d need to go 3-7 the rest of the way to match that, and considering seven of the remaining ten games are against teams with serious playoff aspirations, the struggle is real. It may well come down to the final series against San Diego, if the Diamondbacks are to avoid finishing with their worst run of any point in the last fourteen years.