Which Relief Pitcher is Worth Acquiring via Trade?

Four acquisition candidates were previously identified.

This AZ Snake Pit article named four relief pitchers worth acquiring based on six criteria:

• Must be a power pitcher whose average fastball velocity is at least 94 MPH with a strikeout/walk ratio of at least 3.
• Must be age 30 or younger.
• Must not have started games because starters command higher (unaffordable) salaries.
• Must have pitched to at least 100 batters in 2022. Less than that greatly increases the risk of a bad acquisition. Albeit that all acquisitions are risky.
• Desirable candidates will improve next season. My approach was to look at relievers who pitched for three teams with poor or below-average defense: The Nationals, the Red Sox, and the Pirates. That has an additional advantage of a possible win-win trade because the Diamondbacks could offer players with above-average defensive abilities.
• Desirable candidates have a poor save percentage.

The candidates to acquire via trade were John Schreiber, David Bednar, Hunter Harvey, and Victor Arano. The following table shows they met all the criteria with the possible exception that David Bednar’s save percentage was too good. Nevertheless, he met the other criteria.

2022 Season. Data from Baseball Reference and Baseball Savant.

Is there an addition consideration that will make our decision easier?

Strikeouts are important. My view is that there are four types of strikes – penalty strike for batter delay of game (very rare), foul ball strikes (and the ball may be caught for an out), called strikes where the batter looks but does not swing, and the batter swings and misses (often called a whiff). Let’s focus on two types of strikes: called strikes and whiffs.

The following graph shows a trend in the Majors is for an increased percentage of swinging strikes per pitch. In the last five years, the Diamondbacks have an opposite trend of decreasing swinging strikes. In 2022 their 10.8% swinging strikes per pitch was significantly below the average of 12.2% in the Majors.

Data from Baseball Savant.

If the Diamondbacks acquire a relief pitcher who has a high rate of swinging strikes, the downward trend could be reversed (albeit that in 2022 the downward trend was stopped with a very small increase). Let’s have another look at our four acquisition candidates.

Which of the four candidates would be the best acquisition?

The following table compares the four candidates.

2022 Season. Data from Baseball Savant.

The table shows Bednar has the best overall statistics:

• All pitches in all counts: Bednar has the lowest Balls In Play (BIP) per pitch.
• All pitches in all counts: Bednar has the highest strikes per pitch.
• 2-strike counts: Bednar has the second lowest BIP per pitch.
• 2-strike counts: Bednar has the highest strikes per pitch.

Strikingly, the table shows that for all four pitchers prior to reaching 2-strikes, most strikes are called strikes, and after reaching 2-strikes, most strikes are swinging strikes. Looking at the ratio of called strikes and swinging strikes revealed:

• Prior to reaching 2-strikes, Bednar had the second most whiffs to called strikes.
• After reaching 2-strikes, Bednar had the most whiffs to called strikes.

In summary, the statistics for whiffs and BIPs show David Bednar to have the best statistics of the four candidates. Let’s focus on him.

Would the Pirates trade David Bednar?

My view is the Pirates are open to trading David Bednar based on a fan poll and quotes from SB nation articles. Details follow:

A mid-season poll of Pirates fans had the following results for most likely Pirate to be traded:

• 27% Daniel Vogelbach
• 26% Bryan Reynolds
• 25% David Bednar
• 22% Chris Stratton

“In what was a constant roster shuffle due to additions through minor trades and waiver claims, the Pirates never achieved consistency from any of their relievers.” — Austin Bechtold of SB Nation

The team’s only All-Star did come from this position group in David Bednar, and he finished the season leading the team with 19 saves. The 28-year-old local boy got off to a blazing hot start this past season, racking up six-plus-out saves like they were going out of style, but things slowed down for The Renegade as the season wore on and he struggled with injuries.

He did finish with a 2.61 ERA, a 1.123 WHIP, and 69 strikeouts in 51 innings to go along with a 3-4 record. He’ll be back next season as the bullpen anchor, though with the way the Buccos are run, it’s not out of the question that he’s dealt as well.” — Darren Yuvan of SB Nation

“Pittsburgh Pirates: They are tearing everything down, so David Bednar and Chris Stratton should both be available at the right price.” — Matt Collins of SB Nation, 16 November 2022

Summary.

Four main points follow:

• The Diamondbacks need to improve their swinging strikes, which in the last four years has fallen significantly below the average in the Majors.
• Four trade candidates met six criteria per a previous article.
• Of the four candidates, David Bednar allows the lowest balls in play and has the highest strike rate. He would improve the Diamondbacks swinging strike rate.
• It’s possible that the Pirates are open to trading David Bednar to the Diamondbacks.