Seng-Lai Tan
Born : 1971 Cat. M55 Ultrarunner since 2008 USA
56
DUV-index ?Largest integer N such that the runner has at least N credited races of at least N km.
60
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
8
Countries visited ?CANCanadaFRAFranceGBRUnited KingdomHKGHong KongISLIcelandITAItalyMASMalaysiaUSAUnited States
73,2%
Rank quotient ?This runner's calculation uses 129 eligible race(s): Σ(rank − 1) = 10 468; Σ finishers = 14 309. 10 468 / 14 309 × 100 = 73.16%. A win adds 0 to the numerator. Lower is better.

Totals

Ultras completed129
Km — ultra races8 774 km
> 100 km7
> 160 km5
> 24h6
Longest race160,9 km

Km per year (ultra races)

486
7 races
2022
582
7 races
2023
545
9 races
2024
1 070
12 races
2025
181
3 races
2026

Race types (share of distance)

Road8,4%
Trail91,6%

Wins & podiums (ultra)

🏆 Win0
🏆 Win M0
🏅 Top 32
🏅 Top 3 M2
Longest winning streak0
Current streak0

HISTORY

129 race(s)
DateRacePerf.Rk
2026
06.06 12h USA2nd Death by Staircase 12hr 50.211 km7
26.04 50mi USA52nd Jack Bristol Lake Waramaug 50mi Ultra Marathon 12:13:52 h45
18.04 50km USA17th Traprock 50k Ultramarathon 8:55:51 h73
2025
06.12 100mi USA3rd Festivus 100 Miler Trail Run 35:16:57 h18
15.11 80km HKG12th TransLantau 80 by UTMB 23:48:22 h462
01.11 30h USA11th The Hamsterwheel 30 Hour Run 96.560 km75
18.10 30h USA17th Ghost Train Rail Trail Race 30 Hours 111.094 km151
04.10 24h USA12th NJ One Day 24 Hour Race 99.779 km15
07.09 50km MAS1st Tunggul Melati Trail 14:43:21 h60
16.08 50km USA3rd Fabulous Fahnestock Trail Races 11:24:54 h62
26.07 50mi USA19th Burning River 50 Mile Endurance Run 15:01:19 h170
18.07 100mi USA36th Vermont 100 Mile Endurance Race 29:45:42 h211
07.06 12h USA1st Death by Staircase 12hr 50.211 km6
29.03 24h USA6th Vernal Equinox 24 Hour Race 80.467 km14
12.01 50km USA15th Crystal Springs 50 km Winter Trail Run 7:37:48 h22
2024
31.12 50mi USA3rd Run Undead Ultra Trail Party 15:10:20 h9
07.12 37.5mi USA2nd Festivus 37.5 Miler Trail Run 10:23:37 h8
30.11 50km USA11th Ghost of Seattle Marathon 7:11:49 h15
16.11 31.5mi USA1st CT Donut Run 7:08:28 h13
19.10 30h USA16th Ghost Train Rail Trail Race 30 Hours 97.204 km138
06.07 50km USA3rd The Aliza Lapierre Fan Club 50k 9:56:03 h20
08.06 12h USA3rd Death by Staircase 12hr 56.487 km2 🥈
18.05 50km USA2nd Free Spirit 50 K 7:00:08 h37
09.03 50km USA20th Bel Monte 50 km Endurance Run 10:08:39 h33
2023
31.12 100mi USA2nd Run Undead Ultra Trail Party 34:44:50 h20
25.11 50km USA10th Ghost of Seattle Marathon 7:14:37 h27
14.10 30h USA15th Ghost Train Rail Trail Race 30 Hours 120.703 km90
16.09 50km USA7th Free to Run 50 km 9:39:15 h6
19.08 50km USA1st Fabulous Fahnestock Trail Races 10:44:13 h73
27.05 100km USA18th Trail Festival at Pineland Farms (Gunstock TrailFest) 12:55:25 h7
18.03 50km USA9th Sycamore Canyon 50k 9:21:00 h22
2022
31.12 100km USA1st Run Undead Ultra Trail Party 17:49:00 h3 🥉
15.10 45mi USA14th Ghost Train Rail Trail Race 45 Mile 11:22:47 h30
16.07 100km USA14th Vermont 100 km Endurance Race 19:14:17 h64
07.05 50km USA27th McDonald Forest 50K Trail Run 10:35:42 h169
23.04 50km USA11th Double Top 50 km 11:05:00 h16
12.03 50km USA9th Old West Trails 50km Race 8:00:52 h67
15.01 39.3mi USA5th Daufuskie Island Ultra Marathon 8:35:06 h15
2021
13.11 50km USA12th Rosaryville Veterans Day 50K 7:54:21 h100
30.10 50km USA10th Nashville 50 km Ultra Marathon 6:36:55 h32
2019
14.09 50mi USA13th Headlands Hundred 50 Mile Endurance Run 18:45:22 h65
20.07 100km USA12th Vermont 100 km Endurance Race 19:49:28 h49
06.07 50km USA5th Lovers Leap of Faith 50 km 8:46:30 h12
22.06 50km USA6th Catamount Ultra Marathon 7:16:16 h135
25.05 50km USA14th Jemez Mountain 50km Trail Run 11:36:56 h179
11.05 50km USA9th Ultra Race of Champions (UROC) 50K 8:01:49 h48
09.03 50mi USA6th Antelope Canyon 50 Mile Race 14:43:24 h238
26.01 50km USA3rd AZT Oracle Rumble 50 km 8:53:57 h66
12.01 50km USA9th Steep Ravine 50 km Trail Run 7:52:14 h27
2018
25.08 50km USA2nd Mountain Running Series - Killington 9:00:03 h76
23.06 40mi USA2nd Many On The Genny 40 Mile Trail Ultra 10:55:42 h83
27.05 50mi USA13th Trail Festival at Pineland Farms 11:04:31 h122
20.05 50km USA1st Watuppa Trail Race 50km 5:50:10 h18
05.05 50km USA2nd Wildflower Trail Run 7:06:53 h38
21.04 53km ITATuscany Crossing 50 km 7:03:28 h152
07.04 50km USA5th Runamuck 50K 6:56:01 h89
2017
03.09 50km USA6th Jay Peak 50k Ultra Trail Race 7:23:44 h10
22.04 60km GBRFox Ultra 8:12:31 h117
24.03 50mi USA7th Badger Mountain 50 Mile Challenge 12:30:29 h46
2016
12.11 50mi USA7th Stone Mill 50 Mile Run 12:55:26 h182
24.09 50mi USA3rd Endurance Challenge - Utah Trail 50 Miles 14:31:19 h84
16.07 48km CAN2nd Quebec Mega Trail 7:26:15 h134
18.06 12h USA10th 12 hour Running with the Devil 48.280 km7
04.06 50mi USA4th Cayuga Trails 50 Mile Race 14:46:36 h173
29.05 50mi USA11th Trail Festival at Pineland Farms 10:33:41 h95
19.03 50mi USA5th Fort Clinch 50 Mile Endurance Run 13:17:13 h37
30.01 50km USA6th Bandit Ultra 50K Trail Run 7:48:32 h69
2015
27.12 50km USA14th Woodside Trail Run 50K 6:12:48 h43
08.11 50km USA7th Potomac Heritage Trail 8:10:00 h31
12.09 100km USA4th Pine Creek Challenge 100 km 15:09:05 h22
18.07 55km ISL19. Laugavegurinn 55 km, Landmannalaugar - Húsadalur 8:57:22 h346
23.05 50km USA10th Jemez Mountain 50km Trail Run 10:03:13 h137
02.05 50mi USA8th Endurance Challenge - New York Trail 50 Miles 14:01:58 h297
12.04 50km USA2nd Cape Cod 50K Trail Race 6:40:05 h21
21.03 80km FRA8ème Le EcoTrail de Paris - Ile de France 80 km 11:53:22 h1425
2014
18.10 50km USA4th TARC Fall Classic 50 km 6:40:38 h38
17.08 100km USA2nd Hampshire 100 - 100K run 14:23:55 h19
09.08 50km USA3rd Wildcat Ridge Romp 50 km 7:31:20 h28
19.07 12h USA8th 12 hour Running with the Devil 53.108 km16
14.06 50km USA1st Vegan Power 50K 6:22:13 h23
24.05 50km USA9th Jemez Mountain 50km Trail Run 10:09:19 h130
26.04 50mi USA22nd Leona Divide 50 Mile Run 12:04:39 h142
06.04 50km USA1st Cape Cod 50K Trail Race 6:22:50 h26
2013
29.12 50km USA12th Woodside Trail Run 50K 6:40:23 h74
15.09 50km USA16th Pisgah Mountain Trail Race 7:05:57 h72
27.04 100km ITATuscany Crossing 100 km 17:25:04 h94
20.04 50mi USA1st Leatherwood Ultras 50 Mile 12:26:00 h35
17.03 50km HKG2nd TransLantau 50 Ultra Trail 12:53:00 h430
03.03 50km USA11th Caumsett Park 50K Lloyd Neck - Open Race 5:05:42 h31
02.02 100mi USA21st Rocky Raccoon 100 Mile Trail Run 24:26:01 h102
2012
15.12 100mi USA3rd The Bartram Forest 100 Mile Race 29:32:40 h20
18.11 50km USA3rd Spooner's Cove 50 km Trail Run 7:05:18 h6
28.09 50km USA4th Mountain Madness 50K 7:22:59 h46
21.07 12h USA6th 12 hour Running with the Devil 65.000 km7
30.06 50mi USA24th Finger Lakes Fifties 50 Mile Run 11:58:51 h33
27.05 50mi USA7th Trail Festival at Pineland Farms 10:58:22 h110
21.04 50mi USA4th Labor of Love 50 Mile Race 12:15:54 h15
14.04 50km USA3rd Traprock 50k Ultramarathon 8:02:45 h85
04.02 50mi USA20th Rocky Raccoon 50 Mile Trail Run 12:19:55 h171
22.01 50km USA1st Brooks Falls Trail 6:54:47 h11
2011
03.12 100km USA1st Cajun Coyote 100 km Trail Run 16:04:00 h17
15.10 50mi USA2nd Endurance Challenge - Georgia Trail 50 Miles 13:49:56 h132
21.05 50km USA6th Jemez Mountain 50km Trail Run 11:04:13 h136
23.04 50km USA37th Lake Waramaug 50km Ultra Marathon 5:53:39 h34
2010
18.12 50km USA1st Seth’s Fat Ass 50K 5:39:25 h9
16.10 50km USA1st Defiance 50k 5:43:54 h34
11.09 50mi USA4th Bartlett Park Ultras 50M 11:09:16 h5
17.07 50km USA1st Soaring Eagle 50 km Trail Run 6:07:10 h10
08.05 50km USA2nd Lost Lake 50k 8:05:12 h24
04.04 50km USA1st Soaring Eagle 50 km Trail Run 6:04:22 h9
06.02 50km USA9th Woodside Trail Run 50K 5:31:54 h26
2009
21.11 50mi USA47th JFK 50 Mile 9:44:43 h341
10.10 100km USA1st Oil Creek 100 km Trail Run 10:38:40 h15
19.09 50mi USA2nd Endurance Challenge - Washington D.C. Trail 50 Miles 10:54:05 h110
18.04 50mi USA6th Desert Rats Trail Running Festival 50 Miles 12:57:51 h40
28.02 50km USA6th Pony Express 50K Sprint 5:42:44 h7
24.01 50km USA5th Pigtails Run 50K 5:00:00 h14
10.01 50km USA14th Bridle Trails Winter Running Festival 5:12:34 h18
2008
25.10 50mi USA1st Endurance Challenge - Wisconsin Trail 50 Miles 9:56:30 h64
28.09 50mi USA15th Vermont 50 Miles Ultra Run 11:19:12 h124
13.09 50km USA14th Cle Elum Ridge 50k 7:18:00 h57
09.08 50mi USA2nd Headlands Hundred 50 Mile Endurance Run 11:19:48 h45
19.07 50km USA4th Sequoia Trail Run 6:08:56 h22
20.06 50mi USA17th Bighorn Mountain Wild & Scenic 50mi Trail Run 13:49:57 h91
31.05 50km USA2nd The 20th Century 50K Trail Run 5:17:15 h5
10.05 50km USA1st Endurance Challenge - Washington Trail 50 km 8:08:13 h32
13.04 50km USA25th Mt. Si 50 km Ultra Run 5:18:35 h27
15.03 50km USA16th Chuckanut 50K 7:42:09 h280
03.02 50km USA2nd Lord Hill Trail Run 6:47:00 h25