Reference

MLE Translation Factors

Per-component factors for translating MiLB seasons to park-neutral MLB-equivalent rates. Calibrated from 2018–2025 promotion cohorts. League-specific factors take priority over level fallbacks.

■ <0.88 heavy suppression ■ 0.88–0.98 moderate suppression ■ 0.98–1.02 neutral ■ 1.02–1.10 moderate boost ■ >1.10 heavy boost (K% only)

Reading the table: Multiply a player's MiLB rate by the factor to get the park-neutral MLB-equivalent rate. K% factor >1 means strikeout rate increases going to MLB. K%▲ arrow indicates upward direction is a penalty.

Per-League Factors (LEAGUE_MLE)

League	Lvl	BB%	HBP%	K% ▲	1B/BIP	2B/BIP	3B/BIP	HR/BIP
AAA
International League (IL)	AAA	0.690	0.940	1.200	0.930	0.830	0.970	0.840
PCL	AAA	0.710	0.980	1.290	0.900	0.810	0.810	0.780
AA
EL	AA	0.700	0.850	1.280	0.970	0.860	0.950	0.890
SL	AA	0.680	0.840	1.300	0.920	0.910	0.880	0.950
TL	AA	0.700	0.870	1.300	0.920	0.840	0.940	0.910
A+
CAL	A+	0.710	0.790	1.340	0.910	0.820	0.760	0.920
CAR	A+	0.630	0.860	1.420	0.940	0.830	0.800	0.900
FSL	A+	0.750	0.930	1.420	0.920	0.960	0.810	0.880
Midwest League	A+	0.710	0.790	1.270	0.920	0.810	0.850	0.800
South Atlantic League	A+	0.600	0.770	1.310	0.870	0.780	0.850	0.880
A
Low-A East (Low-A West, SAL)	A	0.660	0.770	1.340	0.920	0.820	0.940	0.880
MWL	A	0.710	0.720	1.380	0.920	0.860	0.900	0.850
Other
APP	Other	0.640	0.740	1.420	0.840	0.740	0.740	0.800
AZL (GCL)	Other	0.620	0.720	1.440	0.820	0.720	0.720	0.780
NY-Penn (NWL, NYPL)	Other	0.630	0.740	1.400	0.870	0.760	0.820	0.820
PIO	Other	0.610	0.720	1.440	0.820	0.720	0.720	0.750

Level Fallback Factors (COMPONENT_MLE)

Used when a player's specific league is not in the per-league table above.

Level	BB%	HBP%	K% ▲	1B/BIP	2B/BIP	3B/BIP	HR/BIP
AAA Level fallback	0.690	0.940	1.200	0.930	0.830	0.920	0.840
AA Level fallback	0.690	0.850	1.290	0.940	0.870	0.920	0.920
A+ Level fallback	0.710	0.810	1.350	0.910	0.830	0.820	0.880
A Level fallback	0.690	0.780	1.360	0.920	0.830	0.910	0.860
ROK Level fallback	0.620	0.720	1.440	0.820	0.720	0.720	0.780

Calibration Methodology

Factors are empirically calibrated from promotion cohorts: all players with ≥80 PA at a given MiLB level in year Y and ≥40 MLB PA in year Y or Y+1 (2018–2025 data). For each pair, both ends are park-neutralized using 7-component regressed park factors, then the MLE prediction is compared to actual MLB performance. The ratio (actual / predicted) drives factor updates. Factors weighted by harmonic-mean PA to reward large samples on both ends.

Age adjustment: ±1.0–1.5%/year multiplier on offensive components (not K%) based on player age relative to level average.
GB/FB BABIP: ground-ball rate shifts expected BABIP by ~+0.013 per +0.10 unit above league average (coefficient 0.44, capped ±5%).