Inspiration.
This AZ Snake Pit article identified four possible acquisitions for the Diamondbacks rotation. It looked at quality start percentage, ERA+, seasons with 150 innings pitched, injury risk, and their fastball’s average velocity.
Let’s look further at those four players. Which pitcher would be most worth acquiring?
The last article was published on 4 August. The following table is updated through the end of the regular season. Data from FanGraphs, Baseball Reference, and Baseball Savant.
Between August
and the end of the season, the percentage of quality starts fell for all four pitchers. The lead changed from Framber Valdez (64.5% QS) to Ranger Suarez (65.4%).
The ERA+ fell for all four pitchers. Ranger Suarez’s 137 ERA+ retained the lead.
The average fastball velocity rose for 3 of the four pitchers. Framber Valdez’s 94.3 MPH retained the lead.
What makes an excellent starting pitcher?
The four pitchers passed the initial screening. Let’s look at three additional evaluation factors:
- Pinpoint command of location (where the ball passes the plate/batter).
- Variety of pitches (types of pitches having different movement and velocity)
- Mental strength (perform under pressure and strategic thinking).
The following table shows my subjective evaluation on these evaluation factors. Discussion follows the table.
My subjective evaluation of pinpoint location was informed by a combination of walks per 9 innings, ground ball percentage, and hard hit percentage. Ranger Suarez ranked best in two of three location factors.
Variety of pitches was informed by pitches shown in Baseball Savant.
“The best Suárez starts don’t always look pretty, but they do look funky. It’s never the same pitch twice, never to the same location twice. He’s twice as likely to make you tap one into the ground than to strike you out….” — Ben Clemens
Mental strength was informed by what I’ve read about each pitcher. In the NLDS against the Dodgers, Ranger Suarez’s mental strength impressed me. After giving up a homer run to the first batter faced, he pitched five innings with no runs allowed! His pitching helped break a Dodgers streak of 13 consecutive postseason games with at least 4 runs scored per Terynce Garner.
“…everyone gravitates toward Suarez due to his cool, calm, and collected approach.” — Benjamin Goldstein
What are additional considerations?
Ranger Suarez ranked first on the three evaluation factors (command, variety of pitches, and mental strength). In addition, he led in percentage of quality starts and ERA+.
Looking at the additional considerations, there were two additional strengths and two concerns.
Strength: His 31.1% HH was at the 98th percentile (Baseball Savant), and a career best.
Strength: His 5.5 Barrel % was at the 89th percentile (Baseball Savant)
Concern: in the last three seasons he pitched better in the first half than the second half (OPS against per Baseball Reference). Although my view is that a lot of the difference is explained by great pitching in the first half of the last two seasons, let’s think about it. A better first half season could be acceptable to the Diamondbacks for two reasons. The first reason is that the Diamondbacks intend to start next season strong. The second reason is that in the second half of the season, expect Corbin Burnes (and a couple relievers) to return from the IL.
Concern: He is a left-handed pitcher (and will naturally have an advantage against left handed batters). The concern is how will he do against right-handed batters? The following table compares his splits to Merrill Kelly’s splits. Looking at a simple average of the last two seasons, against right-handed batters, Merrill Kelly has a slight edge (.656 vs .682 OPS against) and against left-handed batters, Ranger Suarez has a big edge (.665 vs .721 OPS against). Overall, Ranger Suarez’s split is not big enough to override the other evaluation factors.
Who is most worth acquiring?
For many reasons, Ranger Suarez is most worth acquiring!
He ranked best:
- Percentage of quality starts.
- Pinpoint command of location.
- Variety of pitches.
- Mental strength.
Although he might pitch better in the first half of the season, that will work well for the Diamondbacks because they need a strong start to the season, and because they have pitchers returning from the injured list.
Although he pitches better against left-handed batters, he also pitches well against right-handed batters.












