04 Jun 100 Minutes Are Not the Same: Why Playing Time Is a Poor Measure of Competitive Load
For decades, football has relied on a simple assumption:
More minutes = more load.
Playing time has become the universal currency used to describe player exposure, accumulated fatigue, squad rotation, workload management, and even injury risk.
But what if playing time tells us how long a player was exposed, rather than how much load they actually accumulated?
That question motivated us to develop a new metric: the Participation Index.
The objective was simple:
To estimate the competitive load accumulated by a player throughout a season, not just the time spent on the pitch.
Building a Fairer Measure of Participation
Using tracking data, every metre covered was weighted according to its movement intensity.
| Movement category | Weight |
|---|---|
| Static (<2 km/h) | 0 |
| Walking | 1 |
| Jogging | 1.5 |
| Running | 3 |
| High-Speed Running | 6 |
| Sprinting | 10 |
The Participation Index was calculated as:
Participation Index =
(Walking × 1) +
(Jogging × 1.5) +
(Running × 3) +
(HSR × 6) +
(Sprint × 10)
Unlike playing time, this approach recognises a simple reality:
Not every minute imposes the same physical demands.
The First Problem: Position Bias
If every player competes for 100 minutes, do they accumulate the same load?
The answer is clearly no.
Our analysis revealed substantial differences between positions.
Wide players accumulated approximately 28% more competitive load than playing time alone would suggest.
Full-backs also accumulated considerably more load than expected.
At the opposite end of the spectrum, centre-backs accumulated substantially less load, while goalkeepers represented the most extreme case, accumulating roughly 72% less locomotor load than their playing time suggested.
This means that playing time systematically:
- Underestimates wide players.
- Underestimates attacking full-backs.
- Overestimates centre-backs.
- Dramatically overestimates goalkeepers.
In other words:
Playing time is not position-neutral.
The Second Problem: Even Within The Same Position, Minutes Fail
One possible explanation would be to argue:
«Of course wide players accumulate more load than centre-backs. That’s obvious.»
And that is true.
But the story does not end there.
We repeated the analysis within each position group.
Players were compared only against others performing similar roles.
The result was revealing.
Even within the same position, playing time still failed to describe competitive load accurately.
Goalkeepers
Most underestimated by playing time
| Player | Difference |
|---|---|
| Joan García | +26.9% |
| Iñaki Peña | +21.1% |
| Dmitrovic | +14.7% |
Most overestimated by playing time
| Player | Difference |
|---|---|
| Adrián | -32.1% |
| David Soria | -23.8% |
| Agirrezabala | -17.0% |
Centre Backs
Most underestimated
| Player | Difference |
|---|---|
| Becerra | +66.1% |
| John C. | +30.6% |
| A. Osambela | +21.9% |
Most overestimated
| Player | Difference |
|---|---|
| F. Gatttoni | -39.0% |
| Pelayo | -28.7% |
| Manuel Serrano | -26.9% |
Full Backs / Wing Backs
Most underestimated
| Player | Difference |
|---|---|
| Sergi Cardona | +17.2% |
| Fran García | +14.3% |
| Álex Pedraza | +13.6% |
Most overestimated
| Player | Difference |
|---|---|
| Ballestero | -77.5% |
| Rubo | -73.6% |
| A. Alti | -62.9% |
Defensive Midfielders
Most underestimated
| Player | Difference |
|---|---|
| Guevara | +18.6% |
| Koke | +17.7% |
| Gumbau | +15.3% |
Most overestimated
| Player | Difference |
|---|---|
| Aguirre | -73.7% |
| Burcio | -72.9% |
| L. Pinillos | -68.6% |
Central Midfielders
Most underestimated
| Player | Difference |
|---|---|
| Fidalgo | +25.5% |
| Guridi | +19.4% |
| Mendoza | +13.8% |
Most overestimated
| Player | Difference |
|---|---|
| D. Pérez | -77.2% |
| Alex S. M. | -70.6% |
| Tommy Marques | -69.8% |
Wide Players
Most underestimated
| Player | Difference |
|---|---|
| Thiago | +31.1% |
| Marín | +20.2% |
| Nico Serrano | +19.5% |
Most overestimated
| Player | Difference |
|---|---|
| Astiazaran | -66.2% |
| A. Leiva | -64.1% |
| S. Lozano | -38.9% |
Strikers
Most underestimated
| Player | Difference |
|---|---|
| P. Durán | +29.6% |
| Kike García | +18.8% |
| I. Romero | +15.9% |
Most overestimated
| Player | Difference |
|---|---|
| Mariezkurrena | -91.4% |
| Rupérez | -85.6% |
| Endrick | -76.8% |
Why This Matters
The key finding is not that positions differ.
We already knew that.
The key finding is that:
Even after correcting for position, playing time remains an imprecise measure of accumulated competitive load.
Two centre-backs with the same minutes can accumulate very different loads.
Two midfielders with identical exposure can experience very different physical demands.
Two wingers can finish the season with radically different competitive burdens despite playing similar amounts of time.
This means that playing time is not simply incomplete.
It is systematically imprecise.
The Real Question
Football has access to detailed tracking data.
We know:
- How much players move.
- How fast they move.
- How often they sprint.
- How much high-speed running they perform.
If all this information is available, why should we continue to estimate competitive load using only minutes played?
The Participation Index does not replace playing time.
Playing time remains an excellent measure of exposure.
But exposure is not load.
And if the objective is to understand the true competitive demands experienced by a player throughout a season, then measuring only minutes means deliberately ignoring a large part of the story.
The evidence is clear:
Not all minutes are created equal.
And perhaps it is time our metrics reflected that reality.