How the projections work
Built on Marcel + MLE translation + scouting + Statcast. Calibrated nightly against ZiPS, Steamer, ATC, FanGraphs Depth Charts, and FG The Board. Updated continuously — this page reflects the current model.
Projection model
Marcel-style 3-year weighted projection. Weights 5/4/3 for hitters, 6/3/1 for pitchers (more recency for volatility-prone arms). Each prior season's PA/BF is discounted by per-level reliability — a 600-PA AA season carries less MLB-quality information than a 600-PA MLB season:
| Level | Hitter | Pitcher |
|---|---|---|
| MLB | 1.00 | 1.00 |
| AAA | 0.75 | 0.70 |
| AA | 0.50 | 0.45 |
| A+ | 0.35 | 0.30 |
| A | 0.25 | 0.20 |
MLE translation
Minor-league rates translated to MLB-equivalent via empirically calibrated factors. For pitchers (K%): AAA × 0.88, AA × 0.81, A+ × 0.77, A × 0.74, ROK × 0.68. HR/BF inflates upward by similar magnitudes — MiLB pitching averages 0.30 HR/9; MLB equivalents are higher. Hitter MLE has separate factors per stat (BB%, K%, ISO, BABIP). Park-adjusted before regression so a Coors hitter regresses toward Coors-context league means.
Scouting blend
FanGraphs + Baseball America scouting grades feed into: (1) HIT-grade target K%/BABIP for prospects, (2) STF/CMD-grade target K%/BB% for pitcher prospects, (3) FLD/ARM-grade fielding runs when MLB innings are thin (less than 400 weighted), (4) SPD-grade SB/PA blend. Scouting weight decays as MLB experience grows — vets project from their stats; prospects from a stats+scouting blend.
Aging curves
Empirically derived per-stat aging deltas applied year-over-year through the forward chain. Hitter wOBA peaks ~age 27, declines ~5 wOBA points per year after 30. Pitcher K% peaks ~age 27; velocity-dependent arms decay faster (Statcast velo + pitch-mix data). Catchers and corner OFs age fastest defensively. Sprint speed declines ~0.22 ft/s/year after 27.
Trade value
Σ (projected WAR × $/WAR by year) − Σ (owed salary), over remaining team-controllable years. $8.0M/WAR base in 2026, +5%/yr through arbitration. Years projecting under 1.0 WAR are excluded (prevents partial-debut years from inflating prospect surplus). Deferred deals NPV-discounted (4% rate over 10-yr horizon). Options exercised by team-vs-player rationality.
WAR composition
Position players: BAT (wOBA-derived), RUN (SB/CS + UBR), FLD (regressed UZR/DRS/OAA + scouting), POS adjustment, REP bonus. Pitchers: FIP-based, replacement FIP 5.30 (SP) / 4.95 (RP, < 80 IP). Runs-per-win 9.8 (calibrated to 2024–25 run environment). Projection cells show park-adjusted by default; toggle for park-neutral.
Calibration & accuracy
Backtested vs ZiPS / Steamer / ATC / FG-DC consensus. Hitter WAR RMSE 0.69 (vs ATC 0.92); pitcher WAR RMSE 0.41. Standings RMSE 5.0 wins; division winners agree 5/6 with FG-DC. Top-100 prospect overlap with FG The Board ~40% (working to close). Sanity checks run after every build (6 specific player assertions).
Recent improvements
R195 — Pitcher pages on the new compact header (matches hitter pages). Pre-arb pitchers (Skenes-tier) now appear in Future Depth Chart projections. SP/RP fallback de-duplicated. Position transitions displace weak incumbents at natural pos. Service-time + control-end shown in player headers.
R194 — Removed FA Fits, Trade Simulator, Future (top-level), Free Agents pages. Header redesign — name + position pill + WAR hero on top, scouting grades inline next to WAR pills + trajectory. Best/Median/Worst case cards removed. Nav consolidated to 4 grouped dropdowns. New FA Targets panel inside per-team Future Depth Chart with Win-Now-Spend vs Budget-Fit scenarios.
R193 — R172 contract pass passes pitcher_comps through (was silently stripping Career Path Comps from every contract holder).
R184-R191 — SP IP floors (age 33-35 + two-of-three workhorse), catcher framing ultra-elite tier, hitter PA targets restored, sub-19 ROK prospect cWAR discount, 11 missing contract extensions, comp Next-3 K%/BB% rendering fix, hitter WAR-card mislabel fix, Hernandez-style young-SP IP growth floor, Arana-style sub-300-PA regression boost.
R174-R177 — UX bug sweep (depth heat, breadcrumbs, title dedup), hitter PA fix (PA shortfall closed), pitcher prospect cWAR boost, catcher framing tighter pull, Awards Race + Competitive Windows pages, Glossary, sticky table headers.
R168 — Survivorship-corrected aging curves (dropout imputation). Closed hitter +0.26 WAR bias to −0.12.
R170 — Industry-grade arbitration: per-year chain WAR + Super-2 + position bonus + raises-only floor.
R166 — Narrative archetype chip with stat-delta sub-line.
R156 — Hitter level reliability + pitcher chain doubt regression.
R153 — Pitcher Marcel BF discounted by per-level reliability.
R130 — Contract overrides (NTC/OPT/DEF badges, NPV discounting).
Questions, errors, suggestions: this is a living model. Every projection is reproducible from the source data.