feat: age grading with the 2025 road tables

[0jonjo]

What

Age grading now uses Alan Jones' 2025 road age-grading tables (approved 2025-01-10 by the USATF Masters Long Distance Running Council) — factors and open standards for 5K, 10K, half marathon and marathon, male and female.

The previous wma_2023_road.yml, despite its name, came from the WMA 2023 track and field tables (howardgrubb.co.uk/athletics/wmatnf23.html): track open standards (5000 m 12:35 / 14:06, 10 000 m 26:11 / 29:01), an outdated women's marathon standard (2:14:04), track keys "1500"/"3000", and factors only from age 30. Road age grades were off by ~1–3%.

Source (primary)

• Repo: https://github.com/AlanLyttonJones/Age-Grade-Tables (pinned commit 4aac6737cb9f216c90a0a610355667cd3d921c61)
• 2025 Files/MaleRoadStd2025.xlsx — sheet "Age Factors" (factors, row "OC sec" = open standard), sheet "AgeStdSec" (age standards, used for the cross-check)
• 2025 Files/FemaleRoadStd2025.xlsx — sheet "Age Facctors" (sic) / "AgeStanSec"
• Columns: "5 km", "10 km", "H. Mar" (21.0975 km), "Marathon" (42.195 km). Factors are "open standard / age standard" (≤ 1), so the gem's seconds * factor and open_standard / age_graded_time are unchanged.
• The four columns are byte-identical to the version uploaded right after approval (commit 43e3cceb88, 2025-01-13); the later commits only changed the male road mile (per the author's commit message, verified by diffing).
• Also verified identical to the AgeGrade.5k/.10k/.hm/.42k text files in 2025 Files/AgeGrade.zip (same repo) and to the data embedded in Howard Grubb's MLDR road calculator 2025 (http://howardgrubb.co.uk/athletics/mldrroad25.html) — the latter used only as a cross-check.

Changes

• lib/calcpace/data/mldr_2025_road.yml (was wma_2023_road.yml): M/F → "5000", "10000", "21097", "42195" → one factor per age, 18–100. Ages > 100 clamp to the age-100 factor; < 18 still refused.
• lib/calcpace/data/mldr_2025_road_open_standards.yml (was wma_2023_open_standards.yml): new meta (source, URL, files), table_version: MLDR_2025_ROAD_ONE_YEAR_FACTORS_V1, open standards M 769/1584/3451/7235 s, F 834/1726/3772/7796 s. Category labels/mins unchanged.
• DATA_PATH, OPEN_STANDARDS_DATA_PATH, WMA_DATA, OPEN_STANDARDS_DATA, TABLE_VERSION keep their names and shapes.
• Module docs, README age-grading section, gemspec description, CHANGELOG ([Unreleased]; no version bump — v1.19.0 is in flight on another branch).
• Tests: official reference cases, open standards, under-30 factors, table coverage 18–100, clamp past 100; boundary test re-pointed (10K 2750 s → 2741 s still lands on exactly 60.0%).

Cross-check (gem vs official)

Official = age standard (AgeStdSec sheet) / time. Grubb = his 2025 calculator's algorithm on his embedded data.

Case	Factor	Gem	Official spreadsheet	Grubb 2025 calc	Before (WMA 2023 track)
Male 40, marathon 3:30:00	0.9783	58.7%	58.69% (7395 s / 12600 s)	58.69%	58.8%
Female 50, marathon 4:00:00	0.8998	60.2%	60.17% (8664 / 14400)	60.17%	62.7%
Female 30, 5K 25:00	0.9959	55.8%	55.80% (837 / 1500)	55.83%	56.4%
Male 60, half 1:50:00	0.8082	64.7%	64.70% (4270 / 6600)	64.70%	63.3%

Baseline diff (gem_realismo/baseline.rb, 1.18.1 vs this branch) — only "Age grade" changes

@@ -18,13 +18,13 @@
 half_marathon 01:45:00 -> marathon: 03:38:55 | 03:30:00 | 03:37:58
 
 ## Age grade (%)
-male 30 5k 00:20:00: 62.9% Local Class (factor 1.0, std 00:12:35)
-male 45 10k 00:45:00: 63.6% Local Class (factor 0.9155, std 00:26:11)
-female 30 5k 00:25:00: 56.4% Intermediate (factor 1.0, std 00:14:06)
-female 50 marathon 04:00:00: 62.7% Local Class (factor 0.8915, std 02:14:04)
-male 60 half_marathon 01:50:00: 63.3% Local Class (factor 0.8264, std 00:57:31)
-female 35 10k 00:50:00: 58.8% Intermediate (factor 0.9869, std 00:29:01)
-male 40 marathon 03:30:00: 58.8% Intermediate (factor 0.9804, std 02:01:09)
+male 30 5k 00:20:00: 64.1% Local Class (factor 0.9999, std 00:12:49)
+male 45 10k 00:45:00: 63.3% Local Class (factor 0.9261, std 00:26:24)
+female 30 5k 00:25:00: 55.8% Intermediate (factor 0.9959, std 00:13:54)
+female 50 marathon 04:00:00: 60.2% Local Class (factor 0.8998, std 02:09:56)
+male 60 half_marathon 01:50:00: 64.7% Local Class (factor 0.8082, std 00:57:31)
+female 35 10k 00:50:00: 58.4% Intermediate (factor 0.9857, std 00:28:46)
+male 40 marathon 03:30:00: 58.7% Intermediate (factor 0.9783, std 02:00:35)
 
 ## Altitude (%)
 0 m: 0.0

Verification

• bundle exec rake test: 513 runs, 1191 assertions, 0 failures, 0 errors, 0 skips
• bundle exec rubocop: 44 files inspected, no offenses detected
• gem build packages both new data files.

[0jonjo]

Superseded by #97 (released as 2.0.0).