Do runners have persistent pacing habits?
Pace retention showed a correlation of 0.50 across consecutive recorded races one calendar year apart, and 0.33 three years apart. There is persistence, but a runner’s earlier pacing pattern is not destiny.
Persistence may reflect the runner, repeated course choices, or shared conditions. It is not an immutable pacing personality.
How we measured it. Use consecutive linked finishes in different years, no more than three years apart, with exactly one recorded eligible finish in each endpoint year. Calculate Pearson correlation between the two 0–20 versus 12.43–24.85 mi pace changes, grouped by calendar-year gap.
Full methodology & sources
For each earlier race pattern, divide the number of next races in each pattern by all eligible pairs with that earlier pattern. These conditional transition percentages sum to 100 within the earlier pattern. Correlation is descriptive; repeat observations of a runner are not independent.
For explicitly audited canonical-ID releases, validate unique matching CORE/FULL ID sets and matching recorded edition/name labels, then join by record ID with matching finish and all nine section durations. Legacy exports retain the one-to-one edition, trimmed lowercase name and full-timing join because their IDs are incompatible. Durations are compared to milliseconds. Keep only supplied non-ambiguous runner identities without conflicting recorded gender, inferred birth years spanning more than two years, or duplicate editions. These are candidate cross-race identities, not independently verified people; unlinked runners are absent. The linkage audit records which join was used.
Use complete, strictly increasing elapsed checkpoints at 3.11, 6.21, 9.32, 12.43, 15.53, 18.64, 21.75, 24.85 and 26.22 mi. Clock strings must parse as H:MM:SS or M:SS. No missing splits are interpolated.
Remove exact duplicate race records, ignoring database IDs, ingestion timestamps and source URLs. Retain finishes from 90 minutes to 12 hours with every section between 3.22 and 32.19 minutes/mi. These quality filters can exclude genuine unusual performances; the analysis describes this eligible cohort, not every entrant.
Full source records are available in public GitHub Releases. These chart tables require at least 100 eligible observations per cell for estimate reliability. Counts refer to finishes, linked pairs or event observations as specified in that answer.
These are observational results. Fitness changes, intentions, training, selection into the dataset and unmeasured conditions can explain differences. Outcome percentiles describe variation among performances, not confidence intervals or advice about the best strategy.
Apply the reviewed source-quality edition exclusions for this exact export after the timing checks. Known invalid split grids, incomplete ingestion, unreconciled HOLD editions and a selected top-finisher field do not contribute to the analyses or prior benchmarks. Report source exclusions separately; an already invalid timing row is not counted twice. Missing age or recorded gender alone does not exclude an otherwise eligible finish from the overall cohort. Other sparse editions are not declared incomplete merely from their size.
Similarity in pace retention between races
Correlation, from −1 to 1
View exact values and sample sizes
| Calendar-year gap | Similarity in pace retention between races | Observations |
|---|---|---|
| 1 | 0.5 | 409,627 |
| 2 | 0.38 | 116,015 |
| 3 | 0.33 | 58,028 |
Pattern in the next recorded race
Percent (%)
View exact values and sample sizes
| Group | Pattern in the next recorded race | Observations |
|---|---|---|
| Faster second 12.43 mi | 2.1% | 209,659 |
| Moderate slowing | 50.1% | 209,659 |
| Pronounced slowing | 34% | 209,659 |
| Similar 12.43 mi blocks | 13.7% | 209,659 |