A history of Arizona Diamondbacks rookies, Part 1: The Seasons

Per Baseball-Reference.com, nineteen players who qualified as rookies appeared for the Diamondbacks in 2016 [Note: Fangraphs additionally lists Enrique Burgos, whom B-R says lost his rookie status after 2015. Throughout, I’m taking B-R as authoritative, and using just bWAR] Those players combined to be worth just 0.4 wins better than replacement level. That seemed like a terribly low value, but there was only one way to find out. So, I went back into the records books and dragged out the stats for all 266 rookie-eligible seasons in team history, 121 position players and 145 pitchers. [Some had multiple eligible years: five position players and two pitchers even had three - most recently Doug Slaten, in 2006-08]

For each year since the Diamondbacks started play in 1998, I added up the WAR for all the rookie position players and pitchers used that year. All told, over those 19 seasons, rookies have given Arizona a total of 43.9 WAR, which works out as an average of 2.3 WAR per season. While that figure does seem lower than you might expect - it means the average rookie Arizona crop is as productive as, for example, Ryan Roberts in 2009 - yes, this year’s harvest was definitely disappointing. However, as we’ll see later, that overall tally is skewed by one remarkable season. If we discount it, the average production over the other 18 seasons drops by almost one-third, to 1.6 WAR per season.

There is also a sharp split between position players and pitchers. The former have averaged less than one win per year, tallying up a total of only 15.7 WAR since the D-backs began. Even allowing for about a 20% advantage in the raw number of seasons, rookie Arizona pitchers have done rather better, posting 28.2 WAR. But once again, that single season (indeed, one particular player, whose name you have probably already figured out!) is responsible for about half of the gap. But it’s hard to be sure if these are good or bad, with no-one to compare them against. So, pausing only to mutter a quick prayer of thanks to the God of Pivot Tables, I repeated the exercise for the other teams in the National League West.

How the West was won?

The table below shows the total rookie WAR for each of the five franchises since 1998. It’s split into position and pitcher WAR, and in each category. I’ve also listed the player, year and WAR of the team’s top rookie during that time.

It’s much of a muchness for the bottom three teams, with only 1.5 WAR covering the Diamondbacks, Padres and Giants. Perhaps surprisingly - considering they’re still awaiting their first division title - it’s the Rockies who occupy second, having picked up over 10 wins more than the third-place D-backs. I was also a bit surprised that they’ve done better with pitchers than hitters: think of Colorado, and the young names that come to mind are more likely hitters, such as Tulo, Nolan Arenado, Todd Helton and, this year, Trevor Story. But this season, their rookie pitchers combined to be worth 4.7 WAR, a number Arizona has matched just that one time in their history.

But the top spot goes to the Dodgers, who have received the best production in the West from both their rookie hitters and pitchers. That lead expanded significantly this season, led by Seager’s top level of production. His 6.1 WAR was third-best in Dodgers’ franchise history, and the best since Mike Piazza put up 7.0 in 1990. All told, their rookie hitters were worth 8.0 WAR and their pitchers 4.1 WAR, for a final score of 12.1 wins. So, while their quarter-billion payroll is certainly giving them some help, and even if 2.4 WAR came from the questionable “rookie” of Kenta Maeda, Los Angeles does appear to be doing a good job of scouting, drafting and developing young talent.

Diamondbacks down the years

How does the figure from 2016 compare to previous years in team history? Time for another table, this time looking only at the numbers per season for Arizona. Again, it’s divided into position players and pitchers, and I’ve included the top rookie for each season. I’ve also included the raw number of rookies used that year, and the number of wins obtained by the team.

Just look at that 2003 season. How good was it? Arizona rookies that year put up more WAR than in every other season from 1998-2013 combined. Obviously, Brandon Webb was a good chunk of that (we’ll discuss his year more in part 2 next week, which looks at individual player seasons). But you could discount his 6.2 WAR entirely, and the total would still be 9.6, close to two wins better than in any other year. For it wasn’t just Webb: 2003 also gave us Oscar Villarreal (2.2 WAR) and Jose Valverde (1.6), while at the plate we got good helpings out of Alex Cintron (2.7) and Lyle Overbay (1.0), as well as a buffet of smaller contributions.

The wheels really fell off the following year though. For the 2004 crop of rookies was, staggeringly, twenty games worse than the 2003 lot. Chad Tracy was the sole rookie to reach even the dizzy heights of one WAR, and his contributions were more than undone by the likes of Edgar Gonzalez (-1.5), Lance Cormier (-1.1) and Andy Green (-1.2). Of the dozen rookie hitters used by the Diamondbacks that year, nine were at -0.3 WAR or worse. They combined for over 1,250 plate-appearances, so basically two full-time players, and a total value of -4.7 WAR. While any direct correlation between rookie production and success is not easy to see in the desert, there’s no doubt that the road to the team’s 111 losses that year was paved with sub-replacement players.

For those who prefer a more visual format, here are the season total numbers from the above chart, in a graph. The blue line is position WAR, the red line is pitcher WAR, and the orange line is overall WAR.

Again, you can see just how incredible the 2003 campaign is. But this also makes it easier to see what seems to be (up until the derailment of 2016, anyway) a steadily increasing output from rookie players, after the nadir which was the BabyBacks AbortionBacks. 2014 and 2015 represented the second- and third-best seasons of rookie production in franchise history, and 2013 comes in fifth. Does this reflect a change in approach, going from the Colangelo to the Kendrick era of ownership? From 1998-2004, the Diamondbacks averaged 1.6 rookie WAR - and, don’t forget, that includes the towering pinnacle of 2003. Since then, rookie WAR has been 64% higher, at a mean of 2.7 WAR.

But last year? Ouch. It was the worst output from Arizona rookie position players since 2010, and the lowest overall figure since 2005. The bad news is, the farm system does not appear to have a Seager or a Webb lurking in the wings, so we’ll just have to hope that the likes of Anthony Banda can help reverse this year’s results, and get the trend going back in the upward direction.