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BOSTON MARATHON 2025

Chi Hang Siu

Bib: 3721•M

0:00
0:00
/ mi
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Overall
#0 / 28404
Top 27%
Gender (Male)
#0 / 16105
Top 39%
Division (M18-39)
#0 / 5642
Race Day Weather
50°/40°F
broken clouds

⏱️ Race Timeline

Course Elevation
7–469 ft
≈
×2stacked redwood trees
•▲ 890 ft climb · ▼ 1342 ft descent
Ribbon color based on
FasterSteadySlower· vs. your average pace
Start
0:00
Race begins
5K· 3.11 mi
6:24/mi
19:54
↑ 97↓ 3451.5%
10K· 6.21 mi
6:32/mi
40:11
↑ 79↓ 1380.4%
15K· 9.32 mi
6:32/mi
1:00:30
↑ 67↓ 78
20K· 12.43 mi
6:43/mi
1:21:21
↑ 106↓ 860.1%
Half· 13.11 mi
6:37/mi
1:25:52
↑ 19↓ 370.5%
25K· 15.53 mi
6:55/mi
1:42:39
↑ 66↓ 880.2%
30K· 18.64 mi
7:33/mi
2:06:06
↑ 181↓ 1480.2%
20M
8:37/mi
2:17:49
↑ 64↓ 500.2%
21M
9:37/mi
2:27:26
↑ 106↓ 241.6%
35K· 21.75 mi
8:32/mi
2:33:49
↑ 17↓ 861.7%
23M
8:31/mi
2:44:29
↑ 23↓ 630.6%
24M
8:41/mi
2:53:10
↓ 821.3%
40K· 24.85 mi
8:42/mi
3:00:36
↓ 200.3%
25.2M
9:25/mi
3:03:51
↑ 13↓ 160.2%
Finish· 26.22 mi
7:51/mi
3:11:51
↑ 22↓ 21

The Course

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Half Splits

1st Half· via HalfFaster
Distance13.11 mi
Time1:25:52
Pace6:33 /mi
2nd Half
Distance13.11 mi
Time1:45:59
Pace8:05 /mi
📊Positive Split: 23.4% slower second half

Checkpoint Splits

CheckpointDistanceTime of DayTimeAvg PaceSegment TimeSegment PaceDiff
5K
3.11 mi10:22:4019:546:2419:54
6:24
-
10K
6.21 mi10:42:5740:116:2820:17
6:32
+0:08
15K
9.32 mi11:03:161:00:306:2920:19
6:32
0:00
20K
12.43 mi11:24:071:21:216:3320:51
6:43
+0:11
Half
13.11 mi11:28:381:25:526:334:31
6:37
-0:06
25K
15.53 mi11:45:251:42:396:3616:47
6:55
+0:18
30K
18.64 mi12:08:522:06:066:4623:27
7:33
+0:38
20M
20.00 mi12:20:352:17:496:5311:43
8:37
+1:04
21M
21.00 mi12:30:122:27:267:019:37
9:37
+1:00
35K
21.75 mi12:36:352:33:497:046:23
8:32
-1:05
23M
23.00 mi12:47:152:44:297:0910:40
8:31
-0:01
24M
24.00 mi12:55:562:53:107:138:41
8:41
+0:10
40K
24.85 mi13:03:223:00:367:167:26
8:42
+0:01
25.2M
25.20 mi13:06:373:03:517:183:15
9:25
+0:43
Finish
26.22 mi13:14:373:11:517:198:00
7:51
-1:34

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

6:24 /mi

Average Pace

7:19 /mi

Slowest Pace

9:37 /mi

Loading chart...
Fastest
Middle
Slowest
Average

📊Segments

Segment Time Comparison

Time at Faster Pace

1:42:39

54% of race

Time at Steady Pace

31:27

16% of race

Time at Slower Pace

57:45

30% of race

Average Pace: 7:19 /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 mi10:22:4019:546:2419:54
6:24
#3159
10K
6.21 mi10:42:5740:116:2820:17
6:32
#3533
15K
9.32 mi11:03:161:00:306:2920:19
6:32
#3627
20K
12.43 mi11:24:071:21:216:3320:51
6:43
#3803
Half
13.11 mi11:28:381:25:526:334:31
6:37
#3825
25K
15.53 mi11:45:251:42:396:3616:47
6:55
#4049
30K
18.64 mi12:08:522:06:066:4623:27
7:33
#4869
20M
20.00 mi12:20:352:17:496:5311:43
8:37
#5681
21M
21.00 mi12:30:122:27:267:019:37
9:37
#6213
35K
21.75 mi12:36:352:33:497:046:23
8:32
#6448
23M
23.00 mi12:47:152:44:297:0910:40
8:31
#6759
24M
24.00 mi12:55:562:53:107:138:41
8:41
#7105
40K
24.85 mi13:03:223:00:367:167:26
8:42
#7328
25.2M
25.20 mi13:06:373:03:517:183:15
9:25
#7428
Finish
26.22 mi13:14:373:11:517:198:00
7:51
#7565
Faster pace
Steady pace
Slower pace

Checkpoint and Segment Rankings

CheckpointDistanceSeg. DistOverallMalesM18-39Seg. OverallSeg. MalesSeg. M18-39
5K3.11 mi3.11 mi3159300230023812(Top 13%)3597(Top 22%)3597(Top 64%)
10K6.21 mi3.10 mi3533-3743352-3503352-3503935(Top 14%)3706(Top 23%)3706(Top 66%)
15K9.32 mi3.11 mi3627-943434-823434-823812(Top 13%)3597(Top 22%)3597(Top 64%)
20K12.43 mi3.11 mi3803-1763587-1533587-1534524(Top 16%)4211(Top 26%)4211(Top 75%)
Half13.11 mi0.68 mi3825-223607-203607-204594(Top 16%)4287(Top 27%)4287(Top 76%)
25K15.53 mi2.42 mi4049-2243806-1993806-1995813(Top 20%)5247(Top 33%)5247(Top 93%)
30K18.64 mi3.11 mi4869-8204503-6974503-6978070(Top 28%)6627(Top 41%)6627(Top 117%)
20M20.00 mi1.36 mi5681-8125176-6735176-67314533(Top 51%)9696(Top 60%)9696(Top 172%)
21M21.00 mi1.00 mi6213-5325575-3995575-39916591(Top 58%)10509(Top 65%)10509(Top 186%)
35K21.75 mi0.75 mi6448-2355741-1665741-16615602(Top 55%)9970(Top 62%)9970(Top 177%)
23M23.00 mi1.25 mi6759-3115927-1865927-18613386(Top 47%)8871(Top 55%)8871(Top 157%)
24M24.00 mi1.00 mi7105-3466133-2066133-20615595(Top 55%)9854(Top 61%)9854(Top 175%)
40K24.85 mi0.85 mi7328-2236250-1176250-11714536(Top 51%)9225(Top 57%)9225(Top 164%)
25.2M25.20 mi0.35 mi7428-1006295-456295-4514042(Top 49%)8927(Top 55%)8927(Top 158%)
Finish26.22 mi1.02 mi7565-1376353-586353-5811758(Top 41%)7897(Top 49%)7897(Top 140%)

Segment Performance Analysis

10K→15K

0.0 - 3.1 mi

Top 13%
×21story building
+97ft-345ft

Overall

3812

Males

3597

M18-39

3597

5K→10K

3.1 - 6.2 mi

Top 14%
×5story building
+79ft-138ft

Overall

3935

Males

3706

M18-39

3706

10K→15K

6.2 - 9.3 mi

Top 13%
×3story building
+67ft-78ft

Overall

3812

Males

3597

M18-39

3597

15K→20K

9.3 - 12.4 mi

Top 16%
×5story building
+106ft-86ft

Overall

4524

Males

4211

M18-39

4211

20K→Half

12.4 - 13.1 mi

Top 16%
×2story building
+19ft-37ft

Overall

4594

Males

4287

M18-39

4287

Half→25K

13.1 - 15.5 mi

Top 20%
×4story building
+66ft-88ft

Overall

5813

Males

5247

M18-39

5247

25K→30K

15.5 - 18.6 mi

Top 28%
×9story building
+181ft-148ft

Overall

8070

Males

6627

M18-39

6627

30K→20M

18.6 - 20.0 mi

Top 51%
×5story building
+64ft-50ft

Overall

14533

Males

9696

M18-39

9696

20M→21M

20.0 - 21.0 mi

Top 58%
×8story building
+106ft-24ft

Overall

16591

Males

10509

M18-39

10509

21M→35K

21.0 - 21.8 mi

Top 55%
×7story building
+17ft-86ft

Overall

15602

Males

9970

M18-39

9970

35K→23M

21.8 - 23.0 mi

Top 47%
×5story building
+23ft-63ft

Overall

13386

Males

8871

M18-39

8871

23M→24M

23.0 - 24.0 mi

Top 55%
×6story building
+12ft-82ft

Overall

15595

Males

9854

M18-39

9854

24M→40K

24.0 - 24.9 mi

Top 51%
×1story
+6ft-20ft

Overall

14536

Males

9225

M18-39

9225

40K→25.2M

24.9 - 25.2 mi

Top 49%
×1story
+13ft-16ft

Overall

14042

Males

8927

M18-39

8927

25.2M→Finish

25.2 - 26.2 mi

Top 41%
×2story building
+22ft-21ft

Overall

11758

Males

7897

M18-39

7897

Passing Analysis

Category:
Athletes Passed
348
Passed By
4754
Net Change
-4406
SegmentAthletes PassedPassed ByNet ChangeStart RankEnd Rank
Start → 5K----#3159
5K → 10K28402-374#3159#3533
10K → 15K70164-94#3533#3627
15K → 20K52228-176#3627#3803
20K → Half628-22#3803#3825
Half → 25K33257-224#3825#4049
25K → 30K28848-820#4049#4869
30K → 20M5817-812#4869#5681
20M → 21M6538-532#5681#6213
21M → 35K12247-235#6213#6448
35K → 23M32343-311#6448#6759
23M → 24M16362-346#6759#7105
24M → 40K19242-223#7105#7328
40K → 25.2M11111-100#7328#7428
25.2M → Finish30167-137#7428#7565
TOTALS3484754-4406
📊

Passing Visuals

Category:
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🔄Passing Circle

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🌊Position Flow

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🏃Race Lanes

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Public Race Data

Boston Athletic Association

Boston Athletic Association

Mika Timing

Mika Timing