{"sport":"mlb","slug":"jack-johnson","bio":{"fullName":"Jack Johnson","position":"X","team":null,"heightInches":null,"weightLbs":null,"birthDate":null,"rookieSeason":1938,"lastSeason":1939,"status":"RET","externalIds":{"mlbam":"818756","chadwick":"078f9de8","retro":"johnj112","wikidata":"Q105742106"}},"draft":null,"statTables":[{"id":"batting","label":"Batting","columns":[{"key":"g"},{"key":"ab"},{"key":"r"},{"key":"h"},{"key":"doubles"},{"key":"triples"},{"key":"hr"},{"key":"rbi"},{"key":"sb"},{"key":"bb"},{"key":"so"},{"key":"avg"},{"key":"obp"},{"key":"slg"},{"key":"ops"}],"rows":[{"season":1938,"seasonType":"REG","team":"Homestead Grays","gamesPlayed":18,"values":{"g":18,"ab":62,"r":12,"h":17,"doubles":1,"triples":1,"hr":3,"rbi":15,"sb":0,"bb":4,"so":null,"avg":0.274,"obp":0.318,"slg":0.468,"ops":0.786},"rowScope":"team"},{"season":1939,"seasonType":"REG","team":"Toledo Crawfords","gamesPlayed":4,"values":{"g":4,"ab":15,"r":3,"h":3,"doubles":1,"triples":0,"hr":1,"rbi":1,"sb":0,"bb":2,"so":null,"avg":0.2,"obp":0.294,"slg":0.467,"ops":0.761},"rowScope":"team"}],"careerTotals":{"REG":{"g":22,"ab":77,"r":15,"h":20,"doubles":2,"triples":1,"hr":4,"rbi":16,"sb":0,"bb":6,"so":null,"avg":0.26,"obp":0.313,"slg":0.468,"ops":0.781}}},{"id":"advanced","label":"Advanced (League-Relative)","columns":[{"key":"ops_plus","label":"OPS+","description":"On-base plus slugging vs the player's own season+league (100 = league average). Park-unadjusted; OBP uses a consistent (H+BB)/(AB+BB) rate. Higher is better.","format":"int","higherIsBetter":true},{"key":"era_plus","label":"ERA+","description":"Earned-run average vs the player's own season+league (100 = league average). Park-unadjusted. Higher is better.","format":"int","higherIsBetter":true}],"rows":[{"season":1938,"seasonType":"REG","team":"Homestead Grays","values":{"ops_plus":111,"era_plus":null},"rowScope":"team"},{"season":1939,"seasonType":"REG","team":"Toledo Crawfords","values":{"ops_plus":105,"era_plus":null},"rowScope":"team"}],"careerTotals":{"REG":{"ops_plus":110,"era_plus":null}},"advancedMeta":{"method":"computed in-house from MLB StatsAPI season batting/pitching lines, normalized to each player's own (season, league) baseline","formulas":{"era_plus":"100 * lgERA / playerERA (league ERA = 9 * ΣER / ΣIP over the season+league)","ops_plus":"100 * (OBP/lgOBP + SLG/lgSLG - 1)","career_era_plus":"innings-weighted league ERA / career ERA (B-Ref method)","career_ops_plus":"AB-weighted OBP & SLG against AB-weighted league rates"},"caveats":["PARK-UNADJUSTED: no park-factor data exists in the corpus, so these are league-relative but not park-adjusted (true B-Ref ERA+/OPS+ also divide by a park factor)","OBP baseline uses a consistent (H+BB)/(AB+BB) reached-base rate for BOTH player and league — the source feed carries no HBP or SF, so this is not the full (H+BB+HBP)/(AB+BB+HBP+SF) OBP; SLG is exact from the hit-type columns","league resolved from team code + season (most-recently-founded franchise existing by that season); the same resolver builds the baseline and looks up the player, so ratios stay internally coherent","a (season, league) bucket below the sample floor (3000 AB batting / 1000 IP pitching) yields null — no noisy baselines","regular season only; postseason lines are excluded from league baselines and metrics","AL and NL and each historical/Negro league are normalized separately — never blended across leagues or eras"]}}],"dataSources":["MLB StatsAPI (statsapi.mlb.com — official public league API; facts only, raw payloads not republished)"],"generatedAt":"2026-07-03T03:41:46.470Z"}