Diamondbacks Report, 20-Game Mark: Improving, but Still Work to Do

Diamondbacks Report

Diamondbacks Report, 20-Game Mark: Improving, but Still Work to Do

Here is the Arizona Diamondbacks Report for the 20-game mark…

Slightly more than 10% of the 2021 season has passed, and the Arizona Diamondbacks have a 9-10 record. They came into Atlanta riding a four-game winning streak after a zany three-game series in Cincinnati that ran the full gamut of emotions. There have been surprises from some players, while others have performed as expected. Overall, the team is improving from their rough start, but there is still work to do. (Stats include all games up to April 22, so the first game against the Braves is not here.)

Diamondbacks Position Player Report


Position-wise, the two biggest areas of concern are the offensive production of the first basemen and shortstops. The three players Fangraphs has as first basemen — Pavin Smith, Wyatt Mathisen, and the injured Christian Walker — have all been below the league average in weighted Runs Above Average (wRAA). They have combined for a -3.6 wRAA — in other words, by having them in the lineup instead of the average hitter in the league, the Diamondbacks have scored 3.6 fewer runs. That ranks the Diamondbacks 13th in the 15-team National League for wRAA by first basemen.

Shortstop has been even worse. Nick Ahmed, Josh Rojas, and Geraldo Perdomo — who is at the alternate site — have combined for a -10.6 wRAA, lower than the pitchers. Yes, shortstop is a defense-first position, but this puts the Diamondbacks dead last in the NL for wRAA by shortstops.

Defensively, they also must improve at this position. In Total Zone Runs Above Average (Rtot) — meaning how many runs a team saved by having this player play the position instead of the average fielder in the league — the Diamondbacks are -1. This comes from Josh Rojas (-2) combining with Nick Ahmed (1). Do not get alarmed about Ahmed — only four NL shortstops have a higher Rtot than Ahmed. His defense will be fine, just like it’s been during his entire stint as a Diamondback.

The Diamondbacks are around the league average in offensive production for third basemen (seventh) and right fielders (ninth). Defensively, those positions also need to improve, as both currently have a Rtot of -2.


The catchers and second basemen both lead the NL in wRAA for their respective positions. The left fielders and center fielders both rank second. Leading the way at catcher is Carson Kelly, who continued the roll he was on during the final two weeks of 2020. He is currently batting .351 (13-for-37) with a weighted On Base Average (wOBA) of .519.[1] This gives him a wRAA of 9.0.

Andrew Young’s performance — although he’s only batted four times — has boosted the offensive production both at second base and in left field. (Fangraphs counts his stats for both positions.) However, that is not skewing the stats. At second base, Eduardo Escobar (3.8 wRAA) and Josh VanMeter (1.2 wRAA) are both trending in the right direction. Left fielder David Peralta has recovered nicely from his cold start, improving his average to .269 (18-for-67) with a .348 wOBA and 2.3 wRAA.

The high numbers in center field are due to the red-hot start by the currently injured Ketel Marte. He had a .462 batting average (12-for-26) with a .568 wOBA and 5.8 wRAA when he injured his hamstring during the sixth game of the season. While Tim Locastro and Nick Heath have a negative wRAA, they are barely below average — Locastro is -0.1 and Heath is -0.2. However, their defense has made up for it. In Rtot, Locastro is +2 and Heath is +1.

Diamondbacks Pitcher Report

Overall, the pitching staff has struggled to keep runs off the board, although there have been some strong individual performances that have kept it from being even worse. But let’s begin with the overall pitching staff. They have an ERA-minus of 123 — 14th in the NL. (Remember, the lower, the better. The league average is 100, and each unit is one percentage point away from the league average. Therefore, 123 is 23 percent higher than the league average.) They have surrendered the most hits (176) in the league as well as the most home runs (31). The team is ninth for fewest walks (65) and 11th for most strikeouts (158). In WHIP, the team is 12th (1.407 — league average is 1.245).


(Note: Stats in the table are as a starter only)

With the three most experienced relievers being on either the injured (Joakim Soria and Tyler Clippard) or restricted (Chris Devenski) list, it is surprising that the starters have struggled more than the pen. They are 11th in ERA-minus (136), 14th in Quality Starts (six or more innings pitched and three or fewer runs — most of the time, when a pitcher does this, he wins) as well as Quality Start Percentage (21%), and 12th in WHIP.

Another good way to measure how well a starter pitches is Game Score (GmSc). Every pitcher starts a game with a GmSc of 50. All “good” results add points, while all “bad” results subtract points. If he ends with 50, he had a so-so start — an equal amount of goods and bads. The current National League average is 53, and, for reference, Luke Weaver’s gem against the Reds where he carried a no-hitter into the seventh had a GmSc of 82. As a unit, the Game Score Average (GmScA) for the Diamondbacks is 47, tied for 12th in the NL.

There’s more, though. When the season began, the top three in the pitching rotation were Madison Bumgarner, Merrill Kelly, and Caleb Smith. Smith only lasted three innings in his lone start, giving up three earned runs on five hits for a GmSc of 36. He went to the pen after one start and has flourished — more on that later. Bumgarner and Kelly both have an ERA over 7.50 and an ERA-minus close to 200 (193 for Kelly, 217 for Bumgarner). When combining the starts by these three, the GmScA is 38 (last in the NL), their ERA-minus is 206 (same), the WHIP is 1.734 (same), and hits per nine is 12.02 (same). The other starters in the rotation have a collective ERA-minus of 82 (fourth) and a quality start percentage of 40% (fifth). Their GmScA is 55 (sixth), and their WHIP is 1.116 (fifth).


(Note: Stats in the table are as a reliever only.)

Despite doing better than expected, this is still an area that needs to improve greatly. Although their ERA-minus as a unit is 103 — only 3% higher than the league average — they are 11th in WHIP (1.432, league average for relievers is 1.302) and 13th in opponent batting average (.254). Their inherited runners scored percentage isn’t bad — 29%, right at the league average. However, a stat many aren’t familiar with — the Goose Egg, one of the most telling and effective measurements of clutch late-innings — shows the end results of these bullpen woes.

The Diamondbacks are 10th in Goose Egg Percentage (59.1%). So far in 2021, the league average is 61.6%, with the high being 81.3% (Philadelphia Phillies) and the low being 25.0% (Colorado Rockies). The Diamondbacks have the third-highest broken egg percentage (31.8% — league average is 24.8%). But the biggest black eye comes from the ratio of Goose Eggs to Broken Eggs. Historically, the average ratio is 3:1. This season, the NL ratio is 2.5:1. The Diamondbacks ratio is (gulp) 1.9:1.

Individually, Caleb Smith has been outstanding since moving to relief. He has gone 1-0 with a 0.84 ERA (21 ERA-minus) and a WHIP of 1.031. Only one runner — either charged to him or an inherited runner — has scored with Caleb Smith on the mound in relief thus far. Matt Peacock and J.B. Bukauskas have also done well in a limited sampling. Kevin Ginkel and Yoan Lopez both have an ERA-minus under 100, which is good, but Lopez is trending in the wrong direction as of late. While Alex Young’s ERA-minus is close to the league average, he is upside down on GE-to-BE, with a ratio of 2:3, or 0.7:1.

Looking Ahead

The Diamondbacks have a tough three-game road series in Atlanta before coming home for a pair against the San Diego Padres and four against the Colorado Rockies. After that, they will head east again for another grueling trip, this time heading to Miami for three against the Marlins and New York for three against the Mets. Of note is the fact that the Diamondbacks typically do not play well against the Mets on the road. (And don’t bring up 1999.)

While there are several things to celebrate, especially offensively, there are still areas that need some work. The biggest is getting opponents out without giving up runs, especially in clutch, late-inning situations.

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[1] wOBA weighs walks, hit by pitch, and each type of hit based on the average number of runs each leads to, either by that player driving in another runner or later scoring himself. Read it just like an on-base percentage. Every year, the league average for wOBA is set to be exactly the same as the league average for on base percentage. (Click [1] at the beginning of this footnote to return to the article.)

Players mentioned:
Pavin Smith, Wyatt Mathisen, Christian Walker, Nick Ahmed, Josh Rojas, Geraldo Perdomo, Carson Kelly, Andrew Young, Eduardo Escobar, Josh VanMeter, David Peralta, Ketel Marte, Tim Locastro, Nick Heath, Joakim Soria, Tyler Clippard, Chris Devenski, Luke Weaver, Madison Bumgarner, Merrill Kelly, Caleb Smith, Matt Peacock, J.B. Bukauskas, Kevin Ginkel, Yoan Lopez, Alex Young

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