What is a Performance Index?

The one-sentence answer

A Performance Index is a composite athletic score — for Performance House, a number from 1 to 99 — built by scoring each athlete in six categories against a reference distribution, then aggregating the categories into a single value.

The point of it is not the number itself. It's that one number lets you do things you can't do with raw test results: rank athletes against each other on a single scale, track an individual athlete's all-round development over a season, and answer "is this athlete improving overall?" without staring at six separate trend lines.

What goes into the score

Performance House uses six categories. Each category is computed from one or more test metrics, then converted into a sub-score on the same 1–99 scale as the overall index.

• Speed — top-end velocity. Usually measured from a 40-yard dash or equivalent (60m, flying 10/20m). The athlete's max sprint speed (MSS) is the underlying quantity.
• Acceleration — the first 10 yards / 10 metres. Captures how quickly the athlete reaches top speed, not just whether they get there.
• Agility — change-of-direction performance. Typically a pro-agility (5-10-5), T-test, or 505 result.
• Jump — vertical or broad jump. Both express lower-body explosive output but on different vectors; the platform handles either.
• Power — power output that isn't pure jumping. Often derived from a medicine-ball throw or a peak-power figure from a counter-movement jump on a force plate.
• Relative strength — load lifted divided by bodyweight. A 200 kg back squat from a 75 kg athlete is a fundamentally different statement than the same lift from a 130 kg athlete, and the Performance Index reflects that.

An athlete doesn't need a result in every category to get a Performance Index — missing categories drop out of the weighted average. But the more categories an athlete has data for, the more confidently the overall score reflects their full profile.

How the math actually works

The composite Performance Index is built in three steps.

Step 1 — Compute the sub-score for each category

For each category, the athlete's raw result (e.g. a 4.62-second 40-yard dash) is converted to a percentile against a reference distribution. The percentile gets a small linear rescale to fit the 1–99 range, so the worst plausible result in the reference data lands near 1 and the best lands near 99.

For sprint categories specifically, raw splits are first turned into the underlying biomechanical quantities — maximum sprint speed (MSS) and an acceleration time constant (TAU) — using a mono-exponential sprint model:

Step 2 — Apply category weights

Each category has a weight, and the sub-scores are combined into a single number using those weights. Default weights are balanced (no single category dominates), but the weights are per-organization — a sprint-focused track team will likely lean speed and acceleration; a powerlifting program will lean strength. The 1–99 scale stays consistent regardless of weighting, so you can still compare across organizations if you want to.

Step 3 — Calibrate against a reference population

A score is only meaningful if "the 70th percentile" maps onto something concrete. The reference distributions used in Performance House are calibrated against published NFL Combine population data — see Clark, Rieger & Bruno (2017), Journal of Strength and Conditioning Research. That gives the score realistic spread across the 4.2–5.2 second 40-yard range and similar ranges for the other tests, without forcing you to test your own athletes against professional ones.

Each athlete's reference distribution is also gender- and (where data permits) sport- specific, so a 70 on the women's volleyball reference and a 70 on the men's football reference are comparable in meaning even though the raw numbers behind them are not.

Reading the score: tiers and what they mean

A 1–99 number is precise but not always intuitive. Performance House groups scores into named tiers to give the number some context at a glance:

The tier labels are a shorthand for stakeholders who don't want to think in percentiles. The underlying number is what you actually use to track progress.

What a Performance Index is good for

• Cross-position and cross-sport comparison. A goalkeeper and a winger will have very different test profiles. The PI puts both on the same 1–99 scale.
• Longitudinal tracking. One trend line for "all-round athleticism" instead of six separate ones. Useful for talent ID, for individual reviews, and for justifying training emphasis to athletes and parents.
• Group reporting. Team averages, position-group breakdowns, and cohort comparisons all become straightforward when each athlete is reduced to one number per snapshot.
• Talent identification. A composite score surfaces athletes who are quietly excellent across the board — players who never top any single leaderboard but are above average in everything.

Where the Performance Index falls short

No composite is a substitute for sport-specific assessment. A few things the PI does not and cannot capture:

• Sport-specific skill. Ball control, hand-eye, technical detail, and tactical reading don't show up in test results, and they often decide who plays.
• Aerobic capacity. The six-category default doesn't include VO2max or sustained running tests. For endurance sports, you'd weight strength and power categories down and supplement with separate endurance metrics rather than rely on the composite alone.
• Recovery, sleep, and load. The PI is a snapshot of testable physical qualities. It tells you nothing about how an athlete is currently absorbing training. That's what wellness check-ins and the Acute:Chronic Workload Ratio are for.
• Context. A 75 in January and a 75 in July tell you the athlete held steady — but if July came after an injury layoff and January was post-camp, they mean different things. The number doesn't carry that context; you do.

A worked example

Imagine an 18-year-old college soccer wide midfielder with the following test results:

• 40-yard dash: 4.62 s (electronic, 10-yard split = 1.65 s)
• Pro agility (5-10-5): 4.40 s
• Counter-movement jump: 62 cm height, 4,800 W peak power
• Back squat 1RM: 145 kg at 78 kg bodyweight → relative strength 1.86×

Once each result is converted to a percentile against the men's soccer reference distribution and rescaled to 1–99, you might get sub-scores like: speed 74, acceleration 71, agility 76, jump 81, power 78, relative strength 69. With balanced default weights, the overall Performance Index lands around 75 — Gold tier.

The interesting story isn't the 75. It's the radar — strong jump and agility, slightly weaker relative strength. That's the conversation: the next training block leans strength while protecting the jump base.

How to start using a Performance Index

You don't need a force plate or a timing-gate setup to begin. Three steps:

1. Pick a small test battery that hits four of the six categories — typically a sprint (speed and acceleration in one go), a jump, an agility test, and a strength lift you already program.
2. Run it as the first session of a block, then again 6–8 weeks later. Even two snapshots per athlete give you a trend.
3. Decide what each tier means in your program. The labels mean nothing until you've looked at your own roster and calibrated expectations.

If you want the math, calibration, and reporting handled for you, that's exactly what Performance House does — every test session produces a Performance Index snapshot, a per-category radar, and a tier badge automatically, and the free Starter plan covers up to five athletes forever.

Frequently asked questions