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How Much Depth Is Worth

Depth now throws 25% of a club's innings, and the gap between the best and worst depth in a season averages 18 wins.

Roster Memo research · Updated November 6, 2026 · Every number on this page is computed from the data on each refresh

Every club has nine hitters who take most of its plate appearances and a dozen pitchers who throw most of its innings. Everyone else is depth: the bench, the call-ups, the sixth starter, the arms shuttled up for a week. This study measures what that group is worth, using every club season from 2000 to 2025 except 2020.

Depth's share of the work has grown on the mound. Pitchers outside a club's top five starters and top seven relievers threw 14% of its innings in 2000 and 25% in 2025. Hitters outside the top nine took 28% of plate appearances in 2000 and 27% in 2025, about the same.

A run from depth counts like any other run. In a regression of wins on both groups' runs, a run from the regulars was worth 0.104 wins and a run from depth 0.120: one win for every 8 to 10 runs.

Clubs differ a lot in how good their depth is. One standard deviation of depth quality is worth 4.3 wins. In the average season, the club with the best depth got 18 more wins from it than the club with the worst. The best on record is the 2019 Twins (+14.1 wins against an average club's depth); the worst is the 2024 White Sox (-15.3).

Winning clubs tend to have better depth, but regulars matter more. Clubs on pace for 90 or more wins averaged +3.1 wins from depth and +7.6 from their regulars, against the season's average club. Clubs on pace for 70 or fewer averaged -3.3 and -9.2.

The Evidence

How much of the work goes to depth

Innings thrown by pitchers outside the top five starters and top seven relievers, and plate appearances taken by hitters outside the top nine. Average club.

10%15%20%25%30%35%20002005201020152025SeasonInnings, 2000: 14.4%Innings, 2001: 15.0%Innings, 2002: 14.7%Innings, 2003: 14.1%Innings, 2004: 14.2%Innings, 2005: 13.3%Innings, 2006: 16.6%Innings, 2007: 16.3%Innings, 2008: 15.6%Innings, 2009: 18.3%Innings, 2010: 16.0%Innings, 2011: 15.0%Innings, 2012: 18.3%Innings, 2013: 17.3%Innings, 2014: 17.6%Innings, 2015: 20.3%Innings, 2016: 20.9%Innings, 2017: 22.7%Innings, 2018: 22.1%Innings, 2019: 23.2%Innings, 2021: 26.2%Innings, 2022: 24.2%Innings, 2023: 25.0%Innings, 2024: 23.8%Innings, 2025: 24.7%Plate appearances, 2000: 27.5%Plate appearances, 2001: 26.3%Plate appearances, 2002: 26.1%Plate appearances, 2003: 27.0%Plate appearances, 2004: 25.9%Plate appearances, 2005: 25.2%Plate appearances, 2006: 26.1%Plate appearances, 2007: 25.1%Plate appearances, 2008: 26.8%Plate appearances, 2009: 26.9%Plate appearances, 2010: 27.4%Plate appearances, 2011: 28.3%Plate appearances, 2012: 27.9%Plate appearances, 2013: 27.2%Plate appearances, 2014: 27.4%Plate appearances, 2015: 27.3%Plate appearances, 2016: 26.3%Plate appearances, 2017: 26.8%Plate appearances, 2018: 27.6%Plate appearances, 2019: 28.3%Plate appearances, 2021: 30.2%Plate appearances, 2022: 28.4%Plate appearances, 2023: 27.4%Plate appearances, 2024: 27.1%Plate appearances, 2025: 26.5%Plate appearances 26.5%Innings 24.7%
SeasonInningsPlate appearances
202524.7%26.5%
202423.8%27.1%
202325.0%27.4%
202224.2%28.4%
202126.2%30.2%
201923.2%28.3%
201822.1%27.6%
201722.7%26.8%
201620.9%26.3%
201520.3%27.3%
201417.6%27.4%
201317.3%27.2%
201218.3%27.9%
201115.0%28.3%
201016.0%27.4%
200918.3%26.9%
200815.6%26.8%
200716.3%25.1%
200616.6%26.1%
200513.3%25.2%
200414.2%25.9%
200314.1%27.0%
200214.7%26.1%
200115.0%26.3%
200014.4%27.5%
Source: Roster Memo analysis of Retrosheet data

Best depth minus worst depth, in wins

Each season's gap between the club that got the most from its depth and the club that got the least.

010203020002005201020152025Season2000: 17.52001: 15.82002: 17.62003: 19.62004: 18.22005: 11.32006: 15.02007: 12.32008: 19.82009: 14.72010: 18.92011: 17.82012: 15.02013: 16.22014: 13.12015: 18.32016: 21.52017: 20.42018: 19.02019: 25.22021: 20.62022: 16.22023: 16.72024: 22.22025: 19.419.4
SeasonGap
202519.4
202422.2
202316.7
202216.2
202120.6
201925.2
201819.0
201720.4
201621.5
201518.3
201413.1
201316.2
201215.0
201117.8
201018.9
200914.7
200819.8
200712.3
200615.0
200511.3
200418.2
200319.6
200217.6
200115.8
200017.5
Source: Roster Memo analysis of Retrosheet data

Where wins come from, by type of club

Average wins above the season's average club, from regulars and from depth.

ClubsClub seasonsFrom regularsFrom depth
On pace for 90+ wins205+7.6+3.1
71 to 89393-0.4-0.3
70 or fewer152-9.2-3.3
Source: Roster Memo analysis of Retrosheet data

How We Did It

  • Regulars are each club's nine hitters with the most plate appearances, its five starters with the most starts, and its seven relievers with the most innings. Everyone else is depth.
  • Hitting runs come from wOBA against the league average. Pitching runs come from FIP (strikeouts, walks, hit batters and home runs) against the league average. Each group's runs are then measured against the average club's group that season.
  • Runs become wins through a regression of each club's wins (scaled to 162 games) on both groups' runs, across 750 club seasons.

What This Can't Tell You

  • Defense and baserunning aren't counted, and FIP ignores what happens on balls in play, so this measures hitting and pitching skill only.
  • Bad clubs give more playing time to depth on purpose, to look at young players. Some of the link between depth and losing runs that way.
  • A player traded midseason counts separately for each club.

Sources: Retrosheet. The information used here was obtained free of charge from and is copyrighted by Retrosheet. Interested parties may contact Retrosheet at "www.retrosheet.org".

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