wOBA assigns run values to each offensive outcome based on how much each event contributes to scoring. A home run is worth more than a single, and wOBA captures that gap precisely.

BSI adaptation for college baseball: The weights above are derived from Tom Tango's linear weight methodology as applied to MLB run environments. College baseball has a higher run environment (~5.5 runs/game vs. ~4.5 in MLB), so BSI recalibrates the wOBA scale factor annually to normalize to the D1 OBP baseline.

Stabilization: ~150 plate appearances. Below this threshold, BSI displays the value with a sample-size indicator. The metric is most reliable after conference play begins (Week 6+).

wRC+ answers the question: “How productive is this hitter compared to the league average, adjusted for park and conference?” 100 is average. 120 means 20% better than average. 80 means 20% worse.

Why it matters for college baseball: A .350 hitter at a bandbox in the Big South is not the same as a .320 hitter at Lindsey Nelson Stadium in the SEC. wRC+ strips away the park and conference context to give you a true comparison. It is the single best cross-conference batting metric.

Stabilization: ~200 plate appearances. Most reliable in the second half of the season.

ERA tells you what happened. FIP tells you what the pitcher actually controlled. By isolating strikeouts, walks, hit-by-pitches, and home runs — the outcomes that don't depend on fielders — FIP is a better predictor of future ERA than ERA itself.

The FIP constant: BSI computes a D1-specific FIP constant each season by setting league FIP equal to league ERA. This centers the scale so that a 4.00 FIP means “average for college baseball,” not for MLB.

Stabilization: ~60 innings pitched. Below this, the K/BB ratio is a more reliable indicator of true talent.

ERA- adjusts a pitcher's ERA for park and conference context, then scales to 100. Below 100 is better than average. A pitcher with 80 ERA- allowed 20% fewer runs than the conference-adjusted average. This is the best cross-conference pitching comparison metric — a 3.50 ERA in the SEC is not the same as a 3.50 ERA in the SWAC, and ERA- accounts for that difference.

Every stadium affects offense differently. BSI computes park factors by comparing run-scoring at each venue to the league baseline, then regressing toward 1.0 to account for small sample sizes.

Regression toward 1.0: A park that shows a 1.30 runs factor over 15 games is regressed toward 1.0 more aggressively than a park with 40 games of data. This prevents early-season noise from distorting player metrics. BSI uses a sample-size weighting function: the more games, the more the raw factor is trusted.

Factors computed: Runs, hits, home runs, walks, strikeouts — each with independent regression rates. Currently tracking 195 D1 venues.

The Conference Strength Index combines inter-conference win percentage, average run environment, aggregate wOBA, aggregate ERA, and RPI average into a single composite score. This powers the conference adjustments in wRC+ and ERA-.

Why it matters: A .320 wOBA in the SEC represents fundamentally different offensive production than a .340 wOBA in the Big South. The conference strength index quantifies that difference so that cross-conference player comparisons are meaningful, not misleading.

• No Statcast data. College baseball does not have exit velocity, launch angle, or spin rate tracking at scale. BSI metrics are computed from traditional box score data, not TrackMan/Hawk-Eye data.
• BABIP instability. BABIP requires ~400 plate appearances to stabilize. Most college hitters never reach this threshold in a single season (~200-250 PA). BSI displays BABIP but flags it as high-variance.
• Park factor regression. Early-season park factors are heavily regressed toward 1.0 due to small sample sizes. Mid-season factors (30+ games) are more reliable.
• 6-hour refresh cycle. Advanced metrics update every 6 hours. Live box scores update in real-time, but derived metrics (wOBA, wRC+, FIP) reflect the last compute cycle.