01 The arc regular season · tap or arrow through the seasons

The arc

His ERA was lower than the National League's in of his 18 seasons. The exception was . Put another way: a pitcher with the league's ERA in each of his seasons, over his innings, would have allowed earned runs. Kershaw allowed , which is fewer.

He won the ERA title (the lowest ERA among NL pitchers with at least one inning per team game) in . The honors in the top rows are MLB's own award record for him; the strikeout and win milestones are counted from his game logs.

The marks

DateMarkOpponentHis line

League ERA is every NL team's earned runs per nine innings that season, summed from MLB's team pitching totals, with no adjustment for ballparks. Injured-list stints come from MLB's transaction log for him, which begins in ; reasons are as the team reported them.

02

Pitch by pitch

Baseball Savant has a pitch type for of his regular-season pitches. The four-seam fastball averaged in and in , and went from of his pitches to . The slider, of his pitches in 2008, peaked at in .

The curveball is the pitch Vin Scully called “Public Enemy No. 1,” after one Kershaw threw to Boston's Sean Casey in a spring-training game on March 9, 2008, when he was 6. It was of his pitches that rookie season, fell to in as the slider took over, and stayed between and from on.

Pitch types are Baseball Savant's labels. The tracking under them changed: PITCHf/x from 2008, Statcast from 2015 (batted-ball measurements first appear in his Savant data in ), with Trackman radar through 2019 and Hawk-Eye cameras from 20203. Savant says velocities from 2008–16 are PITCHf/x readings adjusted to roughly the release point, so all seasons are on the same scale2. A one-season jump in a pitch's share can be a labeling change rather than a change in what he threw. Whiff rate is swinging strikes as a share of swings, bunts left out; a pitch type is drawn in a season only with at least pitches (velocity) or swings (whiffs). Intentional balls are left out of the mix.

03

Where he stands

Of the pitchers who debuted in 1920 or later and threw at least 2,000 regular-season innings, Among the who started at least half of their games,

Raw ERA doesn't know how many runs were being scored around a pitcher. Measured against his own league each season (league ERA ÷ his ERA × 100, weighted by his innings, with no park adjustment), Baseball-Reference's version, ERA+, does adjust for ballparks; it has him at 154, tied with Pedro Martínez for fourth on its career leaderboard4.

#PitcherSeasonsIPGS / GERAvs lg

Careers are summed from MLB's season lines for 1920–2025, regular season only. Those lines include the Negro Leagues (); “Vs lg” is the league-relative ERA above; a pitcher traded mid-season is measured against the league he finished in.

04

October, honestly

In the postseason he was with a ERA in innings over games ( starts). In the regular season: .

As a starter he had a ERA in innings; in relief appearances, in . By round: .

For how October differs from the regular season across the league, see How Different Is October?; see also Yamamoto in October.

Postseason by round
RoundGGSIPW–LKERA

Sources & method

  1. Beth Harris, “Clayton Kershaw to retire after 18 years with Dodgers and more than 3,000 strikeouts,” Associated Press, September 18, 2025, as published by WSLS, wsls.com (accessed 8 Oct 2026). The retirement announcement. The story, written before the 2025 postseason, credits him with World Series titles in 2020 and 2024; MLB's award record used on this page lists 2020 and 2025, and he did not pitch in the 2024 postseason.
  2. Baseball Savant (MLB Advanced Media), Statcast Search, pitch-level CSV for pitcher 477132, regular season, one request per season 2008–2025: baseballsavant.mlb.com/statcast_search/csv?all=true&player_type=pitcher&pitchers_lookup[]=477132&hfSea=YYYY|&hfGT=R|&type=details (fetched ). Field definitions, including the note on PITCHf/x velocities, from Savant's CSV documentation (accessed 8 Oct 2026).
  3. MLB.com Glossary, “Pitch-tracking Era (since 2008),” mlb.com/glossary (accessed 8 Oct 2026).
  4. Baseball-Reference (Sports Reference), “Clayton Kershaw Stats,” baseball-reference.com/players/k/kershcl01.shtml, used to spot-check the season lines here; and “Career Leaders & Records for Adjusted ERA+,” baseball-reference.com/leaders/earned_run_avg_plus_career.shtml (both accessed 8 Oct 2026), where Mariano Rivera leads at 205 and Kershaw and Pedro Martínez share fourth at 154.
  5. MLB Stats API (MLB Advanced Media), statsapi.mlb.com/api/v1/, fetched ; use subject to MLBAM's terms. Every other number on this page comes from these endpoints:
    • people/477132/stats?stats=yearByYear,career&group=pitching&gameType=R (and gameType=P): season and career lines.
    • people/477132/stats?stats=gameLog&group=pitching&gameType=R&season=YYYY: every regular-season game, for the milestones and the no-hitter; gameType=F,D,L,W for postseason games by round.
    • people/477132?hydrate=awards: Cy Young, MVP, All-Star, Gold Glove, Clemente, World Series and other awards.
    • transactions?playerId=477132: injured-list placements and activations.
    • teams?sportId=1&season=YYYY and teams/stats?stats=season&group=pitching&gameType=R&season=YYYY&sportIds=1: each team's league, games and pitching totals, for the NL ERA line and the qualifying innings.
    • stats?stats=season&group=pitching&gameType=R&season=YYYY&sportIds=1&playerPool=ALL&limit=2000, 1920–2025: every pitcher's season line, for the ERA titles, league leads and the career table; gameType=P for the postseason league ERA.
    • stats/leaders?leaderCategories=earnedRunAverage (and wins, strikeouts): a cross-check on the computed league leaders.
    • schedule?sportId=1&season=YYYY&gameType=F,D,L,W&teamId=119: postseason game numbers, scores and series results.
    • people?personIds=…: debut dates, to set aside careers that began before 1920; league?leagueIds=…: the names of the leagues other than the AL and NL in those lines.
  6. Jay Jaffe, “The Day Vin Scully Met Public Enemy Number One,” FanGraphs, April 28, 2020, blogs.fangraphs.com (the March 9 spring game against the Red Sox and Sean Casey); and Jon Weisman, “Clayton Kershaw and ‘Public Enemy No. 1,’ 10 years later: Where it all began,” Dodger Thoughts, March 11, 2018, dodgerthoughts.com, which quotes Scully's call (both accessed 8 Oct 2026).
  7. Definitions used here, not taken from a source: ERA = 27 × earned runs ÷ outs. The ERA title goes to the lowest ERA among NL pitchers with at least one inning per team game; a pitcher traded within a season is measured on his NL innings alone. The computed leaders in ERA, wins and strikeouts match the API's leaders endpoint in every season. League-relative ERA = 100 × the innings-weighted league ERA ÷ his ERA, with the league ERA summed from every pitcher's line in that league-season. Runs “fewer than the league” = league ERA × his innings ÷ 9 − his earned runs, summed over seasons. The build script checks that each season's game log adds up to its season line, the seasons to the career line, and Savant's pitch count to the API's within 1.5%.
  8. Clayton Kershaw and Ellen Kershaw, Arise: Live Out Your Faith and Dreams on Whatever Field You Find Yourself (Ventura, Calif.: Regal / Gospel Light, 2011), ISBN 978-0-8307-6086-2; catalog record at bookshare.org (accessed 8 Oct 2026).
  9. Berean Standard Bible, 2 Timothy 4:7, at biblehub.com/bsb/2_timothy/4.htm; the text has been in the public domain since April 30, 2023 (berean.bible/terms.htm; both accessed 8 Oct 2026).
  10. Photo: Arturo Pardavila III, “Kershaw shuts out Mets: 7/23/2015,” Flickr, via Wikimedia Commons, File:Clayton Kershaw on July 23, 2015 (2).jpg, licensed CC BY 2.0 and resized here; it is the photo on his Wikipedia article (accessed 8 Oct 2026). The shutout is from his MLB Stats API game log for that date.

Built by scripts/build_data.py from the sources above; no statistic on this page is typed in by hand. Made by Lawrence Wu with Claude.

Changelog

  • First published.