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Diamond Index · Reference

Glossary

Plain-language definitions and the exact formulas used across Diamond Index.

Documented metrics58
Batting · StandardBatting · AdvancedPitching · StandardPitching · AdvancedTeams & RankingsStandings & SectionsProfiles, Scores & Predictor
Metric guide

Batting · Standard

17 metrics

Traditional offensive counting and rate statistics.

PA

Plate Appearances

Completed trips to the plate recorded by NJ.com.

Source total
AB

At-Bats

Plate appearances that count as official at-bats.

Source total
H

Hits

Singles, doubles, triples, and home runs.

1B + 2B + 3B + HR
1B

Singles

Hits that result in one base.

H − 2B − 3B − HR
2B

Doubles

Hits that result in two bases.

Source total
3B

Triples

Hits that result in three bases.

Source total
HR

Home Runs

Hits on which the batter scores without another play.

Source total
R

Runs

Times the player scores.

Source total
RBI

Runs Batted In

Runs credited to the batter’s plate appearance.

Source total
BB

Walks

Bases on balls.

Source total
HBP

Hit By Pitch

Times reaching base after being hit by a pitch.

Source total
SB

Stolen Bases

Successful stolen-base attempts.

Source total
AVG

Batting Average

Hits per official at-bat.

H ÷ AB
OBP

On-Base Percentage

Share of plate appearances ending in a hit, walk, or hit-by-pitch.

(H + BB + HBP) ÷ PA
SLG

Slugging Percentage

Total bases per at-bat.

(1B + 2×2B + 3×3B + 4×HR) ÷ AB
OPS

On-Base Plus Slugging

Combined ability to reach base and hit for power.

OBP + SLG
BB%

Walk Rate

Walks as a percentage of plate appearances.

BB ÷ PA × 100
Metric guide

Batting · Advanced

7 metrics

Diamond Index run-value and league-adjusted hitting statistics.

ISO

Isolated Power

Extra bases per at-bat beyond batting average.

SLG − AVG
wOBA

Weighted On-Base Average

Values each way of reaching base by its estimated run impact.

[0.7×(BB+HBP) + 0.9×1B + 1.3×2B + 1.6×3B + 2.0×HR] ÷ PA
wRAA

Weighted Runs Above Average

Estimated batting runs above or below the selected league baseline.

[(wOBA − league wOBA) ÷ 1.12] × PA
wRC

Weighted Runs Created

Estimated total runs created.

wRAA + 0.177×PA
wRC+

Weighted Runs Created Plus

Run creation indexed to league average. 100 is average; 120 is 20% above average.

{[(wOBA − league wOBA) ÷ 1.12 + 0.177] ÷ 0.177} × 100
BsR

Baserunning Runs

A simple Diamond Index estimate of value from steals and triples.

0.2×SB + 0.1×3B
Off

Offensive Runs

Total hitting and baserunning value above average.

wRAA + BsR
Metric guide

Pitching · Standard

9 metrics

Traditional pitching workload and result statistics, scaled to seven-inning high-school games.

IP

Innings Pitched

Total innings recorded by the pitcher.

Source total
H

Hits Allowed

Hits surrendered while pitching.

Source total
R

Runs Allowed

All runs scored while the pitcher was responsible.

Source total
ER

Earned Runs

Runs charged as earned.

Source total
BB

Walks Allowed

Bases on balls issued.

Source total
HBP

Hit Batters

Batters hit by a pitch.

Source total
SO

Strikeouts

Batters retired by strikeout.

Source total
ERA

Earned Run Average

Earned runs allowed per seven innings.

ER ÷ IP × 7
WHIP

Walks and Hits per Inning

Average walks plus hits allowed per inning.

(BB + H) ÷ IP
Metric guide

Pitching · Advanced

7 metrics

Rate, defense-independent, and league-indexed pitching measures.

K/7

Strikeouts per Seven

Strikeouts per seven innings.

SO ÷ IP × 7
BB/7

Walks per Seven

Walks per seven innings.

BB ÷ IP × 7
K/BB

Strikeout-to-Walk Ratio

Strikeouts for every walk issued.

SO ÷ BB
FIP

Fielding Independent Pitching

Estimates run prevention from walks, hit batters, and strikeouts using the site’s high-school formula.

[3×(BB + HBP) − 2×SO] ÷ IP + 3.10
ERA−

ERA Minus

ERA indexed to the site baseline. 100 is average and lower is better.

ERA ÷ 3.00 × 100
FIP−

FIP Minus

FIP indexed to the site baseline. 100 is average and lower is better.

FIP ÷ 4.31 × 100
PIT

Pitching Runs Above Average

Estimated runs saved relative to a 3.00 ERA baseline.

(3.00 − ERA) ÷ 7 × IP
Metric guide

Teams & Rankings

9 metrics

Opponent-adjusted team strength and standings metrics.

W–L–T

Record

Wins, losses, and ties.

W–L, or W–L–T when ties exist
Win%

Winning Percentage

Share of possible wins earned; a tie counts as half a win.

(W + 0.5×T) ÷ (W + L + T)
RF

Runs For

Runs scored across resolved games.

Sum of team runs
RA

Runs Against

Runs allowed across resolved games.

Sum of opponent runs
Diff

Run Differential

Scoring margin across the season.

RF − RA
AdjO

Adjusted Offense

Estimated runs per seven innings against an average New Jersey defense.

Iterative opponent adjustment of runs scored; regressed by five league-average games
AdjD

Adjusted Defense

Estimated runs allowed per seven innings against an average offense. Lower is better.

Iterative opponent adjustment of runs allowed; regressed by five league-average games
SOS

Strength of Schedule

Average raw opponent rating across the team’s schedule.

Mean opponent rating
DI

Diamond Index Score

Opponent-adjusted team quality on a 1–99 scale, with 50 at statewide average.

clamp[50 + 18×z(opponent-adjusted rating), 1, 99]Game margins use sign(margin)×log₂(1+|margin|), a 0.18-run home adjustment, 100 rating iterations, and a three-game prior.
Metric guide

Standings & Sections

2 metrics

Conference placement and projected NJSIAA tournament seeding values.

Division Record

Division Record

Wins, losses, and ties against teams in the same conference division.

Division W–L–T
Power Pts

Projected NJSIAA Power Points

Projected tournament-seeding average from the team’s best 16 game values.

sum(best 16 game Power Points) ÷ 16Game Power Points = (Quality + Residual) × OOWP. Win quality = 6; tie = 3. Win residual = 3×opponent wins; loss residual = opponent wins−1; OOWP = .500 + opponent-opponents’ average Win%.
Metric guide

Profiles, Scores & Predictor

7 metrics

How comparisons, game quality, and projected outcomes are produced.

Percentile

Percentile Ranking

The percentage of qualified New Jersey players at or below the player’s value; lower-is-better pitching stats are reversed.

round[(below + 0.5×equal) ÷ qualified pool × 100]Displayed from the 1st through 99th percentile. Hitting qualification is 50 PA; pitching is 15 IP.
Game Score

Completed Game Quality

Blends team quality, matchup balance, and final-score closeness.

0.72×Matchup Quality + 0.28×Closeness
Matchup Quality

Matchup Quality

Rewards strong teams and evenly matched opponents.

0.72×mean(DI scores) + 0.28×max[0, 100 − 1.35×|DI difference|]
Closeness

Game Closeness

Rewards small final margins.

max[0, 100 − 14×run margin]
Projected Runs

Neutral-Field Projected Runs

Combines one team’s adjusted offense with the opponent’s adjusted defense.

team AdjO × opponent AdjD ÷ statewide mean AdjOProjected means are limited to 0.35–18 runs.
Win Probability

Win Probability

Probability one independent Poisson run distribution outscores the other; half of tie probability goes to each team.

P(A>B) + 0.5×P(A=B)
Run Distribution

Projected Run Distribution

Probability of each team scoring exactly 0–11 runs, with 12+ combined.

Poisson: P(R=r)=e^(−μ)×μ^r÷r!
Method note

Constants and source data

Counting statistics and game results originate with NJ.com. Diamond Index recalculates displayed rate, value, team, percentile, and projection metrics from those inputs. League wOBA is calculated from the selected player pool. Historical career and multi-season rates are recalculated from summed components rather than averaging season rates. NJSIAA Power Points follow the current published procedure.