What are the Diamondbacks Playoff Odds?

A good start has raised hopes for a post season appearance

The Diamondbacks have had an excellent start to the season, going 19-14, and are currently 1.5 games up in the NL Wild Card and just a half game back of the Dodgers in the NL West Division.   

Baseball Reference

Eight of their first ten games were against the Dodgers and the other two were against the Padres and they went 6-4. Since then they've faced a somewhat softer schedule, and gone 13-10. They are five games over .500 for the first time since the end of the 2019 season when they finished 85-77. It's still early of course, but not too early to start to think about the sustainability of their current position.

So what do the various statistics sites that make projections and produce playoff odds report make of this team? The below table includes the playoff odds from four separate sites: Baseball Reference, Fangraphs, Baseball Prospectus, and FiveThirtyEight. There is a sizable range, with the average to make the postseason at about 41%

Jack Sommers

Each system runs varying amounts of simulations based on their own in house projections and criteria.  There are links at the bottom of the article for those that wish to dive into the details of how each site creates their playoff odds. In aggregate the above indicates that although the D-backs current position in the standings is that of a playoff team, they still have a ways to go in the 162 game season to establish themselves as a true contender.  That shouldn't be discouraging. These odds have all improved quite a bit since the start of the season, more than doubling. 

The team has scored 172 runs and allowed 161, for a +11 run differential. That works out to a 17-16 pythagorean won-loss record. They've scored 5.21 runs per game which ranks third in the NL, but their 4.88 runs allowed per game ranks ninth.  Were it not for having the league's second or third best rated defense the runs allowed figure would be higher. 

Zac Gallen and Merrill Kelly have been terrific, with 2.53 and 2.75 ERA respectively. But due to the collapse of Madison Bumgarner and his resulting DFA after just four starts, plus an oblique injury to Zach Davies after two starts, the team has been forced to turn to rookies or second year players for 13 starts.   Ryne Nelson, Tommy Henry, Drey Jameson and Brandon Pfaadt have combined for just three quality starts and a 6.45 ERA.   Davies is not expected back in the MLB rotation before May 20th at the earliest.

Their projected starting catcher, Carson Kelly suffered a fractured wrist towards the end of spring training and has not played a game yet. They are using two second year catchers, Gabriel Moreno and Jose Herrera that have a combined career 93 games and 753 innings caught between them. All of that youth in the rotation and behind the plate are not going to project to improve their run prevention by a lot until they actually do so with a little more consistency. 

The offense has been carrying the team but do not project to be quite this good for the rest of the season. Their .314 team BABIP,  (batting average on balls in play, i.e. non homers) is 16 points higher than the league average and fifth highest in baseball.  Their Hard hit percentage however is a little below MLB average, ranking 18th. Because of this and other factors, advanced statistics sites such as Baseball Savant (Statcast) have the D-backs expected batting output ranking 17th in MLB, compared to their rank of 8th in actual output to date. (xwOBA vs wOBA). 

The flip side of all this projection for regression to the mean is that this team definitely have a lot of intangibles going for them. Their manager Torey Lovullo is respected and admired in the clubhouse and the players respond to him.  The team plays hard every day on every play, run the bases as well as any team in the league, and most nights play an elite level defense. And teams full of young players on the ascent sometimes get better more quickly than projection systems can catch up to.  Just the fact we are having this conversation speaks volumes about how far the team has come, even if they still have a long way still to go.

Links:

Baseball Reference Playoff Odds (See explanation highlighted at top of page)

Fangraphs Playoff Odds. (see link at top of page "More information")

Baseball Prospectus Playoff Odds, (Pecota Standings see More information at top)

FiveThirtyEight (see "How this works" at bottom of page