Masao (石橋正夫) Ishibashi
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Ultrarunner since 2015
13
DUV-index ?Largest integer N such that the runner has at least N credited races of at least N km.
29
DUV-index+ ?Largest integer N such that the race distances provide at least N complete segments of N km in total. A single long race may therefore contribute several segments. See the DUV-Index tab for the detailed calculation. calculation details
1
Countries visited ?Japan
Japan61,4%
Rank quotient ?This runner's calculation uses 13 eligible race(s): Σ(rank − 1) = 4 015; Σ finishers = 6 544. 4 015 / 6 544 × 100 = 61.35%. A win adds 0 to the numerator. Lower is better.
Totals
Ultras completed13
Km — ultra races942 km
Longest race100,0 km
19th Tango 100 km Ultramarathon — 15/9/2019
Km per year (ultra races)
2022
2023
2024
2025
2026
Race types (share of distance)
Road100,0%
Records
HISTORY
13 race(s)| Date | Race | Perf. | Rk | |
|---|---|---|---|---|
| 2026 | ||||
| 19.04 | 70km | 17th 70 km Ultra Maranic Osaka |
8:45:29 h | 91 |
| 2025 | ||||
| 19.10 | 60km | 31th River Shimanto 60km |
7:51:23 h | 163 |
| 14.09 | 60km | 23th Tango 60 km Ultramarathon |
8:08:51 h | 288 |
| 20.04 | 70km | 16th 70 km Ultra Maranic Osaka |
9:20:28 h | 124 |
| 2024 | ||||
| 20.10 | 60km | 30th River Shimanto 60km |
7:57:55 h | 259 |
| 15.09 | 60km | 22th Tango 60 km Ultramarathon |
9:15:07 h | 424 |
| 21.04 | 62km | 34th Fuji 3 Lakes 62 km Challenge |
9:43:09 h | 895 |
| 2020 | ||||
| 31.10 | 60km | 1st Lake Biwa Ultra Maranic - 60 km |
7:46:40 h | 18 |
| 2019 | ||||
| 15.09 | 100km | 19th Tango 100 km Ultramarathon |
13:43:13 h | 849 |
| 21.04 | 100km | 11th 100 km Ultra Maranic Osaka |
12:45:42 h | 231 |
| 2017 | ||||
| 23.04 | 100km | 9th 100 km Ultra Maranic Osaka |
13:35:48 h | 303 |
| 2016 | ||||
| 24.04 | 70km | 8th 70 km Ultra Maranic Osaka |
8:35:42 h | 68 |
| 2015 | ||||
| 29.03 | 70km | 1st Osaka Yodogawa 70 km Ultra Marathon |
9:35:47 h | 315 |
| Runner | Races in common |
|---|---|
DUV-index calculation details
| # | Date | Race | Credited km | DUV-index+ |
|---|---|---|---|---|
| ✓ 1 | 15/9/2019 | 19th Tango 100 km Ultramarathon | 100,00 | ×3 |
| ✓ 2 | 21/4/2019 | 11th 100 km Ultra Maranic Osaka | 100,00 | ×3 |
| ✓ 3 | 23/4/2017 | 9th 100 km Ultra Maranic Osaka | 100,00 | ×3 |
| ✓ 4 | 19/4/2026 | 17th 70 km Ultra Maranic Osaka | 70,00 | ×2 |
| ✓ 5 | 20/4/2025 | 16th 70 km Ultra Maranic Osaka | 70,00 | ×2 |
| ✓ 6 | 24/4/2016 | 8th 70 km Ultra Maranic Osaka | 70,00 | ×2 |
| ✓ 7 | 29/3/2015 | 1st Osaka Yodogawa 70 km Ultra Marathon | 70,00 | ×2 |
| ✓ 8 | 21/4/2024 | 34th Fuji 3 Lakes 62 km Challenge | 62,00 | ×2 |
| ✓ 9 | 19/10/2025 | 31th River Shimanto 60km | 60,00 | ×2 |
| ✓ 10 | 14/9/2025 | 23th Tango 60 km Ultramarathon | 60,00 | ×2 |
| ✓ 11 | 20/10/2024 | 30th River Shimanto 60km | 60,00 | ×2 |
| ✓ 12 | 15/9/2024 | 22th Tango 60 km Ultramarathon | 60,00 | ×2 |
| ✓ 13 | 31/10/2020 | 1st Lake Biwa Ultra Maranic - 60 km | 60,00 | ×2 |