What Jerry Koosman's 1968 Season Would Look Like in 1908
What would Jerry Koosman's 1968 season look like if he pitched in 1908 instead? Below, his real 1968 line sits beside a cross-era translation into 1908's run environment — and a live slider lets you drop that season into any year in MLB history.
Jerry Koosman — 1968 (real)
Translated to 1908
Why the translated ERA looks better (lower): 1908 was a lower-offense run environment than 1968 (league ERA 2.98 → 2.40), so every pitcher's ERA scales down. It does not mean Jerry Koosman would dominate modern hitters more — it is the same pitcher re-based to a lower-scoring league.
What this translation does not account for
This is a model, not a prediction. It re-expresses only Jerry Koosman's rate stats against 1908's league run environment — and nothing else. It does not account for the depth of competition (integration, international talent, a vastly larger athlete pool), pitch velocity, modern pitch arsenals (sliders, splitters, sweepers), strength and conditioning, or in-game adjustments and advanced scouting.
So a higher translated line means 1908 was simply a higher-offense era — not a claim that Jerry Koosman would actually perform better against today's pitching.
Rate Stats: Real vs. Translated
These rate stats are re-expressed by holding Jerry Koosman's performance relative to his league constant and re-basing it on 1908's averages (the same idea behind OPS+/ERA+).
| Stat | 1968 (real) | 1908 (modeled) |
|---|---|---|
| ERA | 2.08 | 1.68 |
| WHIP | 1.10 | 1.05 |
Counting Stats (1968, as played)
| Wins | 19 |
| Losses | 12 |
| Games | 35 |
| Games Started | 34 |
| Strikeouts | 178 |
| Shutouts | 7 |
| Complete Games | 17 |
| Innings | 263.2 |
Why counting totals aren't translated: scaling a counting stat by the league environment ratio massively over-inflates era outliers — e.g. a 1920s slugger's home runs would balloon to absurd modern totals. So home runs, RBI, wins, strikeouts and the like are shown exactly as Jerry Koosman produced them.
Verdict
This is a model, not a prediction. In the Deadball era — a pitcher-dominated, nearly home-run-free game — a run environment easier to pitch in than 1968's (league ERA 2.98 → 2.40) — one reasoned way to express Jerry Koosman's 1968 season is roughly a 1.68 ERA and 1.05 WHIP. That holds his dominance relative to his league constant and re-bases it on 1908's averages; it is not a claim that Jerry Koosman would actually post those numbers. His counting totals (19 W, 178 K) are shown exactly as he pitched them, because scaling counting stats across eras wildly inflates outliers.
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Jerry Koosman in Other Eras
View Jerry Koosman's full profile → · Browse all era translations →