"Koufax's best WHIP in a season is an amazing 0.855. Halladay's never gone under 1.00 in a full season. Koufax struck out 160 more batters in a single year than Halladay has --- that's a full season worth of strikeouts for most pitchers, yet that's just the difference between these two greats."
Neither adjusts for Koufax playing in a preposterous pitchers park or in a low run-scoring era, or Koufax getting to pitch to pitchers and Halladay often not, or modern backups in AL East being far more dangerous than 150-lb SSs in the 1960s. At least ERA+ adjusts; Koufax's peak is better, although at the extremes even that number gets trickier (few total runs being scored, period, in that park).
Neither adjusts for Koufax playing in a preposterous pitchers park or in a low run-scoring era, or Koufax getting to pitch to pitchers and Halladay often not, or modern backups in AL East being far more dangerous than 150-lb SSs in the 1960s. At least ERA+ adjusts; Koufax's peak is better, although at the extremes even that number gets trickier (few total runs being scored, period, in that park).
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