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BOSTON MARATHON 2026

Nathan Koster

Bib: 8815•M

MN

Boston Marathon logo
0:00
0:00
/ mi
Masters
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Overall
#0 / 29021
Top 12%
Gender (Male)
#0 / 16340
Top 20%
Masters (Masters Men)
#0 / 10617
Top 7%
Age Group (M40-44)
#0 / 2198
Top 20%
Race Day Weather
51°/41°F
overcast clouds

Race Timeline and Course Information

Your journey through the course with elevation, pacing, and checkpoint details

⏱️ Race Timeline

Watch your race unfold from start to finish

Start
0:00:00
Race begins
5K
20:55
3.11 mi
Rank: #6180
Start → 5K
20:55 | 6:44/mi
10K
41:41
6.21 mi
Rank: #5967 (+213)
5K → 10K
20:46 | 6:42/mi
15K
1:02:10
9.32 mi
Rank: #5543 (+424)
10K → 15K
20:29 | 6:36/mi
20K
1:22:36
12.43 mi
Rank: #5149 (+394)
15K → 20K
20:26 | 6:35/mi
HALF
1:27:02
13.11 mi
Rank: #5097 (+52)
20K → HALF
4:26 | 6:31/mi
25K
1:42:53
15.53 mi
Rank: #4841 (+256)
HALF → 25K
15:51 | 6:33/mi
30K
2:03:32
18.64 mi
Rank: #4516 (+325)
25K → 30K
20:39 | 6:39/mi
20M
2:12:31
20.00 mi
Rank: #4353 (+163)
30K → 20M
8:59 | 6:37/mi
21M
2:19:24
21.00 mi
Rank: #4228 (+125)
20M → 21M
6:53 | 6:53/mi
35K
2:24:07
21.75 mi
Rank: #4133 (+95)
21M → 35K
4:43 | 6:19/mi
23M
2:32:15
23.00 mi
Rank: #3952 (+181)
35K → 23M
8:08 | 6:30/mi
24M
2:38:31
24.00 mi
Rank: #3830 (+122)
23M → 24M
6:16 | 6:16/mi
40K
2:44:00
24.85 mi
Rank: #3720 (+110)
24M → 40K
5:29 | 6:25/mi
25.2M
2:46:21
25.20 mi
Rank: #3670 (+50)
40K → 25.2M
2:21 | 6:49/mi
FINISH
2:52:34
26.22 mi
Rank: #3535 (+135)
25.2M → FINISH
6:13 | 6:07/mi

Splits & Pacing

Detailed breakdown of your race performance at each timing point

Half Splits

1st Half
via HALF
Distance13.11 mi
Time1:27:02
Pace6:39 /mi
2nd Half✓ Faster
Distance13.11 mi
Time1:25:32
Pace6:32 /mi
📊Negative Split: 1.7% faster second half

Checkpoint Splits

CheckpointDistanceTime of DayTimeAvg PaceSegment TimeSegment PaceDiff
5K
3.11 mi10:36:1320:556:4420:55
6:44
-
10K
6.21 mi10:56:5941:416:4320:46
6:42
-0:02
15K
9.32 mi11:17:281:02:106:4120:29
6:36
-0:06
20K
12.43 mi11:37:541:22:366:3920:26
6:35
-0:01
HALF
13.11 mi11:42:201:27:026:394:26
6:31
-0:04
25K
15.53 mi11:58:111:42:536:3815:51
6:33
+0:02
30K
18.64 mi12:18:502:03:326:3820:39
6:39
+0:06
20M
20.00 mi12:27:492:12:316:388:59
6:37
-0:02
21M
21.00 mi12:34:422:19:246:396:53
6:53
+0:16
35K
21.75 mi12:39:252:24:076:384:43
6:19
-0:34
23M
23.00 mi12:47:332:32:156:388:08
6:30
+0:11
24M
24.00 mi12:53:492:38:316:376:16
6:16
-0:14
40K
24.85 mi12:59:182:44:006:365:29
6:25
+0:09
25.2M
25.20 mi13:01:392:46:216:372:21
6:49
+0:24
FINISH
26.22 mi13:07:522:52:346:366:13
6:07
-0:42

Checkpoint Splits Visualizations

Explore your race data through different visual perspectives. Scroll to discover each visualization.

📈Pace Line

Pace Progression

Track your pace changes throughout the race. Dot colors mark your quickest to easiest segments, relative to your own pace.

Fastest Pace

6:07 /mi

Average Pace

6:35 /mi

Slowest Pace

6:53 /mi

Loading chart...
Fastest
Middle
Slowest
Average

📊Segments

Segment Time Comparison

Bar length shows time spent in each segment. Colors mark your faster to slower segments, relative to your own pace.

Time at Faster Pace

2:22:25

83% of race

Time at Steady Pace

30:09

17% of race

Time at Slower Pace

0:00

0% of race

Average Pace: 6:35 /mi

Loading chart...
Faster pace (< avg)
Steady pace (≈ avg)
Slower pace (> avg)

🎨Heatmap

Pace Heatmap

Where you sped up and eased off relative to your own pace across the race. Colors are relative to your own range, not to other runners.

Loading...
0mi6.6mi13.1mi19.7mi26.2mi
Pace:
Faster
Steady
Slower

Click or hover over segments to see details

✨Sparklines

Checkpoint Splits with Pace Trends

Enhanced split table showing pace trends through mini sparkline visualizations.

Overall Pace Trend

CheckpointDistanceTime of DayTimeAvg PaceSegmentPaceTrendRank
5K
3.11 mi10:36:1320:556:4420:55
6:44
#6180
10K
6.21 mi10:56:5941:416:4320:46
6:42
#5967
15K
9.32 mi11:17:281:02:106:4120:29
6:36
#5543
20K
12.43 mi11:37:541:22:366:3920:26
6:35
#5149
HALF
13.11 mi11:42:201:27:026:394:26
6:31
#5097
25K
15.53 mi11:58:111:42:536:3815:51
6:33
#4841
30K
18.64 mi12:18:502:03:326:3820:39
6:39
#4516
20M
20.00 mi12:27:492:12:316:388:59
6:37
#4353
21M
21.00 mi12:34:422:19:246:396:53
6:53
#4228
35K
21.75 mi12:39:252:24:076:384:43
6:19
#4133
23M
23.00 mi12:47:332:32:156:388:08
6:30
#3952
24M
24.00 mi12:53:492:38:316:376:16
6:16
#3830
40K
24.85 mi12:59:182:44:006:365:29
6:25
#3720
25.2M
25.20 mi13:01:392:46:216:372:21
6:49
#3670
FINISH
26.22 mi13:07:522:52:346:366:13
6:07
#3535
Faster pace
Steady pace
Slower pace

Rankings

Your position at each checkpoint and how you ranked in each segment

Checkpoint and Segment Rankings

CheckpointDistanceSeg. DistOverallMalesM40-44Seg. OverallSeg. MalesSeg. M40-44
5K3.11 mi3.11 mi6180560656064857(Top 17%)4535(Top 28%)4535(Top 206%)
10K6.21 mi3.10 mi5967+2135447+1595447+1595773(Top 20%)5279(Top 32%)5279(Top 240%)
15K9.32 mi3.11 mi5543+4245119+3285119+3284857(Top 17%)4535(Top 28%)4535(Top 206%)
20K12.43 mi3.11 mi5149+3944789+3304789+3304257(Top 15%)4013(Top 25%)4013(Top 183%)
HALF13.11 mi0.68 mi5097+524745+444745+444362(Top 15%)4110(Top 25%)4110(Top 187%)
25K15.53 mi2.42 mi4841+2564528+2174528+2173673(Top 13%)3479(Top 21%)3479(Top 158%)
30K18.64 mi3.11 mi4516+3254241+2874241+2873384(Top 12%)3186(Top 19%)3186(Top 145%)
20M20.00 mi1.36 mi4353+1634089+1524089+1523014(Top 10%)2835(Top 17%)2835(Top 129%)
21M21.00 mi1.00 mi4228+1253970+1193970+1192840(Top 10%)2654(Top 16%)2654(Top 121%)
35K21.75 mi0.75 mi4133+953878+923878+922554(Top 9%)2410(Top 15%)2410(Top 110%)
23M23.00 mi1.25 mi3952+1813710+1683710+1682430(Top 8%)2286(Top 14%)2286(Top 104%)
24M24.00 mi1.00 mi3830+1223593+1173593+1172080(Top 7%)1960(Top 12%)1960(Top 89%)
40K24.85 mi0.85 mi3720+1103498+953498+952193(Top 8%)2044(Top 13%)2044(Top 93%)
25.2M25.20 mi0.35 mi3670+503454+443454+441949(Top 7%)1815(Top 11%)1815(Top 83%)
FINISH26.22 mi1.02 mi3535+1353331+1233331+1232064(Top 7%)1906(Top 12%)1906(Top 87%)

Segment Performance Analysis

10K→15K

0.0 - 3.1 mi

Top 17%
×21
+97ft-345ft

Overall

4857

Males

4535

M40-44

4535

5K→10K

3.1 - 6.2 mi

Top 20%
×5
+79ft-138ft

Overall

5773

Males

5279

M40-44

5279

10K→15K

6.2 - 9.3 mi

Top 17%
×3
+67ft-78ft

Overall

4857

Males

4535

M40-44

4535

15K→20K

9.3 - 12.4 mi

Top 15%
×5
+106ft-86ft

Overall

4257

Males

4013

M40-44

4013

20K→HALF

12.4 - 13.1 mi

Top 15%
×2
+19ft-37ft

Overall

4362

Males

4110

M40-44

4110

HALF→25K

13.1 - 15.5 mi

Top 13%
×4
+66ft-88ft

Overall

3673

Males

3479

M40-44

3479

25K→30K

15.5 - 18.6 mi

Top 12%
×9
+181ft-148ft

Overall

3384

Males

3186

M40-44

3186

30K→20M

18.6 - 20.0 mi

Top 10%
×5
+64ft-50ft

Overall

3014

Males

2835

M40-44

2835

20M→21M

20.0 - 21.0 mi

Top 10%
×8
+106ft-24ft

Overall

2840

Males

2654

M40-44

2654

21M→35K

21.0 - 21.8 mi

Top 9%
×7
+17ft-86ft

Overall

2554

Males

2410

M40-44

2410

35K→23M

21.8 - 23.0 mi

Top 8%
×5
+23ft-63ft

Overall

2430

Males

2286

M40-44

2286

23M→24M

23.0 - 24.0 mi

Top 7%
×6
+12ft-82ft

Overall

2080

Males

1960

M40-44

1960

24M→40K

24.0 - 24.9 mi

Top 8%
×1
+6ft-20ft

Overall

2193

Males

2044

M40-44

2044

40K→25.2M

24.9 - 25.2 mi

Top 7%
×1
+13ft-16ft

Overall

1949

Males

1815

M40-44

1815

25.2M→FINISH

25.2 - 26.2 mi

Top 7%
×2
+22ft-21ft

Overall

2064

Males

1906

M40-44

1906

Passing

Athletes you passed and who passed you throughout the race

Passing Analysis

Category:
Athletes Passed
2817
Passed By
172
Net Change
+2645
SegmentAthletes PassedPassed ByNet ChangeStart RankEnd Rank
Start → 5K----#6180
5K → 10K328115+213#6180#5967
10K → 15K4339+424#5967#5543
15K → 20K3973+394#5543#5149
20K → HALF542+52#5149#5097
HALF → 25K2593+256#5097#4841
25K → 30K3349+325#4841#4516
30K → 20M1663+163#4516#4353
20M → 21M1327+125#4353#4228
21M → 35K994+95#4228#4133
35K → 23M1865+181#4133#3952
23M → 24M1297+122#3952#3830
24M → 40K1133+110#3830#3720
40K → 25.2M500+50#3720#3670
25.2M → FINISH1372+135#3670#3535
TOTALS2817172+2645
📊

Passing Analysis Visualizations

Explore your passing analysis through 5 different visualizations. Scroll to discover each one.

Time:
Category:

📈Position Graph

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🎨Heatmap Timeline

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🔄Passing Circle

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🌊Position Flow

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🏃Race Lanes

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Qualifying & Age Grade

See how your performance stacks up against qualifying standards

OTQ

Olympic Trials Qualifying analysis available

Activity Data

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Export & Support

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Public Race Data

Boston Athletic Association

Boston Athletic Association

Mika Timing

Mika Timing