100 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.

Note: data excludes this afternoon’s game against Atlanta.

The last 10 games

Arizona is 4-6 over the last ten games. This is not great. We lost ground against the Cubs (8-2) and Rockies (6-4). But - and this is what matters - we actually gained ground on the Brewers, who are only 3-7 since then. This is important because we have four teams going for three spots, and to make the post-season, the D-backs only need to be better than the WORST of our rivals. The Cubs can win all they want: it’ll give them the National League Central crown, which is basically irrelevant to our situation. For the D-backs to hit significant trouble in terms of getting a wild-card, it also needs the Rockies and Brewers to get hot as well. [Home-field advantage aside, obvs]

The projection systems

• Baseball Prospectus: 86.8% (0.1% div, 86.7% wildcard)
• Fangraphs: 81.8% (0.1%, 81.7%)
• FiveThirtyEight: 70% (<1%, 70%)
• NumberFire: 86.4% (0.0%, 86.4%)

There was a decline in our odds, but a lot less than you’d think from certain comments on social media. As little as 2.6% over 10 games, according to Fangraphs, and no more than 8%, from FiveThirtyEight, which has recently tended to be the most pessimistic. It’s the Brewers who saw their chances really take a hit since we last checked. On July 15, they had a 35.8% chance of a playoff spot, according to Fangraphs. That has now dropped all the way to 12.3%, little more than one-third of what it was. Their division advantage over the Cubs has evaporated: they trail the Cardinals in playoff odds, and are basically tied with the Pirates, in Fangraphs’ eyes.

The division though... It’s basically all over bar the shouting, and not even the loss of Kershaw for 4-6 weeks is going to change that. It doesn’t seem to have dented the Dodgers’ optimism though, having reeled off four more wins since the Amish farmer trudged off the mound, looking even more disgruntled than usual. Here’s the chart from Fangraphs - which, because I forgot to take a screenshot this morning, does include this afternoon’s win over Atlanta.

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
 35-27 (pace)     40-23         103-59
 33-29            38-25          98-64
 31-31 (.500)     36-27          93-69
 29-33            34-29          87-75
 28-32            33-30 (pace)   85-77
 27-35            32-31          82-80

The Cubs’ surge has certainly narrowed the gap a bit. But bear in mind, as discussed above, we would now need both the Cubs and the Brewers, since they are virtually tied, to perform at the necessary level above, in order to to deprive the Diamondbacks of a spot.

Previous history

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.

For once, history provides a chilling note, with not much more than half of the teams that went 57-43, as we did, going on to reach the post-season. None of the eight teams finished with more than 88 wins, all but one of them (the 82-win Red Sox in 2002) being in the 85-88 win range. The high end of that range, the 2007 Mets, would represent the D-backs going .500 the rest of the way, which is certainly not impossible. But 2007 was fairly extraordinary. No National League team won more than 90 games, yet four won 89 or 90. I don’t see the Cubs, Rockies AND Brewers all making it that high, especially with the Dodgers and Nationals on pace to win 98+

However, the little more than 50/50 nature of the historical record does drag the overall prediction down. Combining all five projections, we get a D-backs playoff percentage of 76..8%, which is down more than eight percent from last time’s 85.0%. But the next ten games have started well, with this afternoon’s victory over the Braves, even if a tough road-trip is about to start.