Boston Marathon logo
BOSTON MARATHON 2023

Spencer Clason

Bib: 4458•M

CO

0:00
0:00
/ mi
Be the first to cheer!
Overall
#0 / 26622
Top 18%
Gender (Male)
#0 / 15176
Top 30%
Division (M18-39)
#0 / 5285
Race Day Weather
49°/39°F
light intensity drizzle

⏱️ Race Timeline

Start
0:00:00
Race begins
5K· 3.11 mi
21:16
Rank: #5099
Start → 5K
21:16 | 6:51/mi
10K· 6.21 mi
42:37
Rank: #5482 (-383)
5K → 10K
21:21 | 6:52/mi
15K· 9.32 mi
1:03:31
Rank: #5126 (+356)
10K → 15K
20:54 | 6:44/mi
20K· 12.43 mi
1:24:36
Rank: #4917 (+209)
15K → 20K
21:05 | 6:47/mi
Half· 13.11 mi
1:29:12
Rank: #4907 (+10)
20K → Half
4:36 | 6:45/mi
25K· 15.53 mi
1:45:38
Rank: #4700 (+207)
Half → 25K
16:26 | 6:47/mi
30K· 18.64 mi
2:07:18
Rank: #4566 (+134)
25K → 30K
21:40 | 6:58/mi
20M
2:16:56
Rank: #4558 (+8)
30K → 20M
9:38 | 7:05/mi
21M
2:24:40
Rank: #4656 (-98)
20M → 21M
7:44 | 7:44/mi
35K· 21.75 mi
2:29:56
Rank: #4678 (-22)
21M → 35K
5:16 | 7:02/mi
23M
2:39:50
Rank: #4912 (-234)
35K → 23M
9:54 | 7:54/mi
24M
2:47:39
Rank: #5062 (-150)
23M → 24M
7:49 | 7:49/mi
40K· 24.85 mi
2:53:49
Rank: #5018 (+44)
24M → 40K
6:10 | 7:13/mi
25.2M
2:56:20
Rank: #4979 (+39)
40K → 25.2M
2:31 | 7:18/mi
Finish· 26.22 mi
3:03:11
Rank: #4875 (+104)
25.2M → Finish
6:51 | 6:43/mi

The Course

Is this your race?

Claim it — unlock a deeper AI report on this race, free

A personalized Race Performance Report that goes beyond this page — emailed to you, built from your real splits.

Half Splits

1st Half· via HalfFaster
Distance13.11 mi
Time1:29:12
Pace6:48 /mi
2nd Half
Distance13.11 mi
Time1:33:59
Pace7:10 /mi
📊Positive Split: 5.4% slower second half

Checkpoint Splits

CheckpointDistanceTime of DayTimeAvg PaceSegment TimeSegment PaceDiff
5K
3.11 mi10:23:4421:166:5121:16
6:51
-
10K
6.21 mi10:45:0542:376:5221:21
6:52
+0:01
15K
9.32 mi11:05:591:03:316:4920:54
6:44
-0:08
20K
12.43 mi11:27:041:24:366:4821:05
6:47
+0:03
Half
13.11 mi11:31:401:29:126:484:36
6:45
-0:02
25K
15.53 mi11:48:061:45:386:4816:26
6:47
+0:02
30K
18.64 mi12:09:462:07:186:5021:40
6:58
+0:11
20M
20.00 mi12:19:242:16:566:519:38
7:05
+0:07
21M
21.00 mi12:27:082:24:406:537:44
7:44
+0:39
35K
21.75 mi12:32:242:29:566:545:16
7:02
-0:42
23M
23.00 mi12:42:182:39:506:579:54
7:54
+0:52
24M
24.00 mi12:50:072:47:396:597:49
7:49
-0:05
40K
24.85 mi12:56:172:53:497:006:10
7:13
-0:36
25.2M
25.20 mi12:58:482:56:207:002:31
7:18
+0:05
Finish
26.22 mi13:05:393:03:117:006:51
6:43
-0:35

Checkpoints & Pacing

📈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

6:43 /mi

Average Pace

7:00 /mi

Slowest Pace

7:54 /mi

Loading chart...
Fastest
Middle
Slowest
Average

📊Segments

Segment Time Comparison

Time at Faster Pace

2:37:44

86% of race

Time at Steady Pace

25:27

14% of race

Time at Slower Pace

0:00

0% of race

Average Pace: 6:59 /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

Overall Pace Trend

CheckpointDistanceTime of DayTimeAvg PaceSegmentPaceTrendRank
5K
3.11 mi10:23:4421:166:5121:16
6:51
#5099
10K
6.21 mi10:45:0542:376:5221:21
6:52
#5482
15K
9.32 mi11:05:591:03:316:4920:54
6:44
#5126
20K
12.43 mi11:27:041:24:366:4821:05
6:47
#4917
Half
13.11 mi11:31:401:29:126:484:36
6:45
#4907
25K
15.53 mi11:48:061:45:386:4816:26
6:47
#4700
30K
18.64 mi12:09:462:07:186:5021:40
6:58
#4566
20M
20.00 mi12:19:242:16:566:519:38
7:05
#4558
21M
21.00 mi12:27:082:24:406:537:44
7:44
#4656
35K
21.75 mi12:32:242:29:566:545:16
7:02
#4678
23M
23.00 mi12:42:182:39:506:579:54
7:54
#4912
24M
24.00 mi12:50:072:47:396:597:49
7:49
#5062
40K
24.85 mi12:56:172:53:497:006:10
7:13
#5018
25.2M
25.20 mi12:58:482:56:207:002:31
7:18
#4979
Finish
26.22 mi13:05:393:03:117:006:51
6:43
#4875
Faster pace
Steady pace
Slower pace

Checkpoint and Segment Rankings

CheckpointDistanceSeg. DistOverallMalesM18-39Seg. OverallSeg. MalesSeg. M18-39
5K3.11 mi3.11 mi5099473047304394(Top 17%)4113(Top 27%)4113(Top 78%)
10K6.21 mi3.10 mi5482-3835058-3285058-3285905(Top 22%)5385(Top 35%)5385(Top 102%)
15K9.32 mi3.11 mi5126+3564753+3054753+3054394(Top 17%)4113(Top 27%)4113(Top 78%)
20K12.43 mi3.11 mi4917+2094578+1754578+1754315(Top 16%)4032(Top 27%)4032(Top 76%)
Half13.11 mi0.68 mi4907+104565+134565+134763(Top 18%)4425(Top 29%)4425(Top 84%)
25K15.53 mi2.42 mi4700+2074378+1874378+1873961(Top 15%)3722(Top 25%)3722(Top 70%)
30K18.64 mi3.11 mi4566+1344260+1184260+1184186(Top 16%)3906(Top 26%)3906(Top 74%)
20M20.00 mi1.36 mi4558+84250+104250+104560(Top 17%)4185(Top 28%)4185(Top 79%)
21M21.00 mi1.00 mi4656-984336-864336-865776(Top 22%)5028(Top 33%)5028(Top 95%)
35K21.75 mi0.75 mi4678-224355-194355-195526(Top 21%)4889(Top 32%)4889(Top 93%)
23M23.00 mi1.25 mi4912-2344546-1914546-1919096(Top 34%)6995(Top 46%)6995(Top 132%)
24M24.00 mi1.00 mi5062-1504655-1094655-1099864(Top 37%)7310(Top 48%)7310(Top 138%)
40K24.85 mi0.85 mi5018+444619+364619+364937(Top 19%)4304(Top 28%)4304(Top 81%)
25.2M25.20 mi0.35 mi4979+394585+344585+342991(Top 11%)2746(Top 18%)2746(Top 52%)
Finish26.22 mi1.02 mi4875+1044492+934492+933642(Top 14%)3256(Top 21%)3256(Top 62%)

Segment Performance Analysis

10K→15K

0.0 - 3.1 mi

Top 17%
×21stories
+97ft-345ft

Overall

4394

Males

4113

M18-39

4113

5K→10K

3.1 - 6.2 mi

Top 22%
×5stories
+79ft-138ft

Overall

5905

Males

5385

M18-39

5385

10K→15K

6.2 - 9.3 mi

Top 17%
×3stories
+67ft-78ft

Overall

4394

Males

4113

M18-39

4113

15K→20K

9.3 - 12.4 mi

Top 16%
×5stories
+106ft-86ft

Overall

4315

Males

4032

M18-39

4032

20K→Half

12.4 - 13.1 mi

Top 18%
×2stories
+19ft-37ft

Overall

4763

Males

4425

M18-39

4425

Half→25K

13.1 - 15.5 mi

Top 15%
×4stories
+66ft-88ft

Overall

3961

Males

3722

M18-39

3722

25K→30K

15.5 - 18.6 mi

Top 16%
×9stories
+181ft-148ft

Overall

4186

Males

3906

M18-39

3906

30K→20M

18.6 - 20.0 mi

Top 17%
×5stories
+64ft-50ft

Overall

4560

Males

4185

M18-39

4185

20M→21M

20.0 - 21.0 mi

Top 22%
×8stories
+106ft-24ft

Overall

5776

Males

5028

M18-39

5028

21M→35K

21.0 - 21.8 mi

Top 21%
×7stories
+17ft-86ft

Overall

5526

Males

4889

M18-39

4889

35K→23M

21.8 - 23.0 mi

Top 34%
×5stories
+23ft-63ft

Overall

9096

Males

6995

M18-39

6995

23M→24M

23.0 - 24.0 mi

Top 37%
×6stories
+12ft-82ft

Overall

9864

Males

7310

M18-39

7310

24M→40K

24.0 - 24.9 mi

Top 19%
×1story
+6ft-20ft

Overall

4937

Males

4304

M18-39

4304

40K→25.2M

24.9 - 25.2 mi

Top 11%
×1story
+13ft-16ft

Overall

2991

Males

2746

M18-39

2746

25.2M→Finish

25.2 - 26.2 mi

Top 14%
×2stories
+22ft-21ft

Overall

3642

Males

3256

M18-39

3256

Passing Analysis

Category:
Athletes Passed
1524
Passed By
1300
Net Change
+224
SegmentAthletes PassedPassed ByNet ChangeStart RankEnd Rank
Start → 5K----#5099
5K → 10K77460-383#5099#5482
10K → 15K37014+356#5482#5126
15K → 20K23223+209#5126#4917
20K → Half2515+10#4917#4907
Half → 25K22619+207#4907#4700
25K → 30K20066+134#4700#4566
30K → 20M6759+8#4566#4558
20M → 21M30128-98#4558#4656
21M → 35K3658-22#4656#4678
35K → 23M30264-234#4678#4912
23M → 24M17167-150#4912#5062
24M → 40K6521+44#5062#5018
40K → 25.2M412+39#5018#4979
25.2M → Finish1084+104#4979#4875
TOTALS15241300+224
📊

Passing Visuals

Category:
Loading...

🔥Passing Intensity

Loading...

🔄Passing Circle

Loading...

🌊Position Flow

Loading...

🏃Race Lanes

Loading...

Upload your GPX file

Supports Garmin, Apple Watch, Polar, Suunto, COROS, Strava, and other apps

.gpx files up to 10MB

Export Track Data

Download your race performance as a GPX or TCX file to import into Strava, Garmin Connect, or other fitness apps.

Questions or issues regarding timing data?

If you notice any discrepancies in your timing data or have questions about your results, our support team can help.

Contact Race Support
Share Feedback

Public Race Data

Boston Athletic Association

Boston Athletic Association

Mika Timing

Mika Timing