Red Sox Defense 2024-2025

Red Sox Ranks:
OAA - 25th (-18)
DRS - 5th (+49)
UZR - 25th (-9.7)
ERR - 29th (115)
Innings - 1st (13,081.2)

DRS is actually quite fond of the Red Sox performance, but generally OAA is looked at as the most accurate statistic at measuring team/player defensive performance (other statcast measures such as FRV and RAA can be more useful at times), and the list of teams behind the Red Sox at 25th (Nationals, Marlins, Angels, White Sox, A's) is not flattering.

Innings are relevant as the Red Sox played ~146 more innings than the average team, so the counting stats above seem slightly less dramatic when accounting for the number of innings. UZR moves from 25th to 23rd, for example. However their errors, if playing a mean slate of innings, only reduce to 113.7 which is still 29th - so the adjustment doesn't change the story. (not relevant to the discussion, but the strain on the pitching/bullpen is unlikely to be as pronounced going forward, as the innings were likely heavily luck-dependent)

Largest Postives in OAA (position) - innings:
Wilyer Abreu: +7 (RF) - 921.1
Jarren Duran: +7 (CF) - 810.1
Ceddanne Rafela: +5 (CF) - 631.1
Jarren Duran: +3 (LF) - 611
David Hamilton: +3 (2B) - 266.2
Trevor Story: +2 (SS) - 227.2

Largest Negatives in OAA:
*Connor Wong: -10 (C) - 878.1
Enmanuez Valdez: -8 (2B) - 467.2
Ceddanne Rafaela: -7 (SS) - 647
Rafael Devers: -6 (3B) - 1138.1
Romy Gonzalez: -4 (3B) - 79
Connor Wong: -4 (1B) - 64.2
*Danny Jansen: -4 (C) - 218.2
David Hamilton: -3 (SS) - 433
Romy Gonzalez: -3 (2B) - 130.1
Rob Refsnyder: -2 (LF) - 297.2
Pablo Reyes: -2 (SS) - 13.2
Triston Casas: -2 (1B) - 512 innings
Vaughn Grissom: -2 (2B) - 245 innings
**in FRV as OAA doesn't track catching; FRV tracks runs rather than outs, but these numbers can be looked at as 1 for 1 within ~20% threshold

Below is an extremely simplistic way of improving the defense. Please note that it will be full of small sample size issues, so please take it with a very large grain of salt and rather that criticize please provide alternate opinion/solutions.

Overly Simplistic Fixes:
+2: Reduce Wong's playing time in place of Teel as mid/late-season call-up. This assumes Teel can play a league-average defense at catcher as a rookie OR another player is brought in.
+4: Replace Danny Jansen with Reese McGuire (+1); Jansen has been an average to above-average catcher throughout his career, so it's possible he just needed practice with the staff (or it's a pitching staff issue) while McGuire is an above-average defensive catcher (+10 FRV career).
+4: Replace Valdez' innings at 2B with Vaughn Grissom; Grissom has not been a good defender but he's an upgrade over Valdez who, despite solid range, has been a butcher given his throwing and double-play turning issues.
+4: Replace Romy's time at 2B with David Hamilton; Hamilton was the Red Sox best defensive 2B last season (Sogard was +0 in 99 innings)
+4: Have a league-average defender as backup 3B; Romy struggled both by metrics and visually in his small sample there, hopefully one of the internal options (Hamilton, Rafaela, Grissom, etc.) can produce better results.
+22: A near-full healthy season for Trevor Story; Story was pre-injured when he signed 3 years ago, so hopefully he is now healthy and avoids any freak injury. Rafaela wasn't the issue in 2024, he was just part of a full group at SS that struggled.

+22 overall (+40 improvement) would have ranked 6th in MLB in 2024. Due to injuries and small sample sizes not working out this isn't realistic, but it illustrates that there are internal options which would greatly improve the defense with Story remaining healthy immediately making this team average-to-better defensively.

Opinion for 2025:
- Have Hamilton & Grissom split time at 2B (with Rafaela receiving some time as well)
- Keep Valdez in the minors or trade (too many superior options to consider him - 40-man spot is likely better used elsewhere)
- Look to move on from Romy (I appreciated what he did, but there are now better options)
- Don't trade for a catcher with league-average bat mid-season (catching is not that easy)
- Have McGuire split time with Wong until Teel is ready (competition will be added I'm sure)
- Don't rush the rookies; young players often struggle defensively with errors and mental mistakes

I wonder if the fix is as easy as Story at SS, Hamilton/Girssom platoon at 2B and move on from Wong. I feel it’s hard to say we plan on upgrading pitching but still have Wong go out and catch 100 games.

Is there any evidence that Devers' defense improves with a better shortstop next to him, or is the assumption that Story will simply offset Devers' poor defense? From what I’ve seen, there’s no data to support the former. Looking at Statcast data, there’s no clear correlation between a third baseman's Outs Above Average and the shortstop’s OAA. For example, Devers’ best defensive season (+18, sadly looking more and more like an anomaly each year) came with a collective -9 OAA at shortstop, the same as his worst season (-9). Is there even a strong theoretical link? How often is Story going to make a play on a ball Devers can't get to in the 6 hole? Devers struggled mightily going to his left this year but that has not been a career long issue. He has actually struggled more often going to his right or in during his career. While Story will undoubtedly improve the overall infield defense, I doubt he will suddenly turn Devers into a good or even average third baseman. History suggests Devers will struggle at third regardless of who's beside him.