90 games in: The Arizona Diamondbacks’ playoff odds

Another ten games in the book, so time to revisit the standings, the playoff odds of the various projection systems, and what history tells us has happened to previous teams with the Diamondbacks’ current record.

The last 10 games

Arizona is only 3-7 over the last ten games. However, it’s not the only time this year they’ve had such a streak, having also gone 3-7 from April 28 through May 9. You could argue the earlier run of games was actually worse, because the run differential over them was -12, compared to this current streak’s -7. FIve of the seven defeats have been by a margin of one-run. In those, the Diamondbacks are a combined .217 with runners in scoring position, going 7-for-32. It’s not hard to imagine that a couple more well-timed hits there, could have swung them our way. But I think we’ll all be a great deal happier when those hits start dropping in. Tonight in Atlanta would be fine...

The projection systems

• Baseball Prospectus: 90.3% (0.9% div, 89.3% wildcard)
• Fangraphs: 84.4% (0.4%, 84.1%)
• FiveThirtyEight: 78% (2%, 76%)
• NumberFire: 92.4% (0.8%, 91.6%)

Definitely a step back - but perhaps not as much as you’d think based on the weeping, wailing and lamentations emanating out of some quarters. The decrease was 10% at most and 3.7% at least. What has happened, is our division hopes have all but evaporated, with three of the four systems now putting those at less than 1%. Which makes sense if you look at the top spots in the West/Wild-card chase, after game #80 and now.

• #1. Dodgers - Dodgers
• #2. Diamondbacks (2.5 GB) - Diamondbacks (8.5 GB)
• #3. Rockies (6 GB) - Rockies (10.5 GB)
• #4. Cubs (12 GB) - Cubs (17 GB)

We’ve lost six games in the standings over the past 10 against the Dodgers, but only one against the Cubs. Which is where we come to our new feature in this section, which we’ll get to, after the usual Fangraphs chart.

Us vs. Them

The table below shows, for a range of outcomes over the Diamondbacks’ remaining games, what the first non-wild card team would currently have to do, to match our record. Even that might not necessarily mean a play-off game however: if the Rockies implode, they could be the ones missing out entirely. I’ve also include what our rival’s required pace is equivalent too, over a full season, to give you a better idea of how well they need to play.

 D-backs go     Rivals go    Season pace
 42-30 (pace)     49-25         107-55
 39-33            46-28         101-61
 36-36 (.500)     43-31          94-68
 33-39            40-34          88-74
 30-42            37-37 (pace)   81-81

This does provide a degree of comfort. If we continue at our current pace, the chasing pack (currently led by the Cubs) would need to win at a 107-game rate the rest of the way. That’s basically turning into the Dodgers. If we only go .500, they would still need to win at a 94-game rate. Considering the Cubs are barely positive in run differential right now, I don’t think even getting Jose Quintana moves the needle that much for them.

Previous 90-game records

I’ve analyzed the results since 1998 of all 570 teams to this point, and whether or not they made the post-season. The chart below breaks down the records, and also lists the teams currently occupying each band in the 2017 standings. I used win percentage to decide their block, on an “at least” basis, e.g. you need at least a .600 W% to get into the 54-36 level.

You can see the table is getting stretched out now, with the Dodgers and Astros a LONG way ahead of the pack, and we are now down to only 10 teams listed, with the other 20 all being in the bottom category. It could well be that those 10 sides are the ones who will be in the playoffs come October. I’d be a bit surprised if we lose more than one of them. As far as the D-backs are concerned, we sit at an 80% chance by historical odds, which is exactly the same as it was after 80 games. But it’s worth noting we are far from safe. Teams with as high as 57 wins - four more than the Diamondbacks - have managed to sit at home for the post-season.

Combining all five projections, we get a D-backs playoff percentage of 85.0%, which is down slightly more than five percent, from last time’s 90.3%. Hopefully, we’ll get things going up again by next time, but we still look a pretty solid bet.