Boston Marathon logo
BOSTON MARATHON 2025

Kai Yun Tsai

Bib: 20430•F

0:00
0:00
/ mi
Masters
Be the first to cheer!
Overall
#0 / 28404
Gender (Female)
#0 / 12228
Masters (Masters Women)
#0 / 6759
Division (F45-49)
#0 / 1813
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
7:43/mi
23:59
↑ 97↓ 3451.5%
10K· 6.21 mi
8:05/mi
49:05
↑ 79↓ 1380.4%
15K· 9.32 mi
8:15/mi
1:14:42
↑ 67↓ 78
20K· 12.43 mi
9:13/mi
1:43:20
↑ 106↓ 860.1%
Half· 13.11 mi
8:56/mi
1:49:26
↑ 19↓ 370.5%
25K· 15.53 mi
9:38/mi
2:12:48
↑ 66↓ 880.2%
30K· 18.64 mi
10:37/mi
2:45:47
↑ 181↓ 1480.2%
20M
11:04/mi
3:00:50
↑ 64↓ 500.2%
21M
12:06/mi
3:12:56
↑ 106↓ 241.6%
35K· 21.75 mi
9:45/mi
3:20:14
↑ 17↓ 861.7%
23M
10:36/mi
3:33:30
↑ 23↓ 630.6%
24M
9:33/mi
3:43:03
↓ 821.3%
40K· 24.85 mi
9:45/mi
3:51:23
↓ 200.3%
25.2M
10:47/mi
3:55:06
↑ 13↓ 160.2%
Finish· 26.22 mi
9:22/mi
4:04:39
↑ 22↓ 21

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
Time1:49:26
Pace8:21 /mi
2nd Half
Distance13.11 mi
Time2:15:13
Pace10:19 /mi
📊Positive Split: 23.6% slower second half

Checkpoint Splits

CheckpointDistanceTime of DayTimeAvg PaceSegment TimeSegment PaceDiff
5K
3.11 mi11:23:5523:597:4323:59
7:43
-
10K
6.21 mi11:49:0149:057:5425:06
8:05
+0:22
15K
9.32 mi12:14:381:14:428:0125:37
8:15
+0:10
20K
12.43 mi12:43:161:43:208:1928:38
9:13
+0:58
Half
13.11 mi12:49:221:49:268:216:06
8:56
-0:17
25K
15.53 mi13:12:442:12:488:3323:22
9:38
+0:42
30K
18.64 mi13:45:432:45:478:5432:59
10:37
+0:59
20M
20.00 mi14:00:463:00:509:0215:03
11:04
+0:27
21M
21.00 mi14:12:523:12:569:1112:06
12:06
+1:02
35K
21.75 mi14:20:103:20:149:127:18
9:45
-2:21
23M
23.00 mi14:33:263:33:309:1713:16
10:36
+0:51
24M
24.00 mi14:42:593:43:039:189:33
9:33
-1:03
40K
24.85 mi14:51:193:51:239:198:20
9:45
+0:12
25.2M
25.20 mi14:55:023:55:069:203:43
10:47
+1:02
Finish
26.22 mi15:04:354:04:399:209:33
9:22
-1:25

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

7:43 /mi

Average Pace

9:20 /mi

Slowest Pace

12:06 /mi

Loading chart...
Fastest
Middle
Slowest
Average

📊Segments

Segment Time Comparison

Time at Faster Pace

1:20:48

33% of race

Time at Steady Pace

1:26:44

35% of race

Time at Slower Pace

1:17:07

32% of race

Average Pace: 9:20 /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 mi11:23:5523:597:4323:59
7:43
#14157
10K
6.21 mi11:49:0149:057:5425:06
8:05
#15677
15K
9.32 mi12:14:381:14:428:0125:37
8:15
#16450
20K
12.43 mi12:43:161:43:208:1928:38
9:13
#18092
Half
13.11 mi12:49:221:49:268:216:06
8:56
#18295
25K
15.53 mi13:12:442:12:488:3323:22
9:38
#19200
30K
18.64 mi13:45:432:45:478:5432:59
10:37
#20342
20M
20.00 mi14:00:463:00:509:0215:03
11:04
#20764
21M
21.00 mi14:12:523:12:569:1112:06
12:06
#21065
35K
21.75 mi14:20:103:20:149:127:18
9:45
#21063
23M
23.00 mi14:33:263:33:309:1713:16
10:36
#21148
24M
24.00 mi14:42:593:43:039:189:33
9:33
#21094
40K
24.85 mi14:51:193:51:239:198:20
9:45
#21046
25.2M
25.20 mi14:55:023:55:069:203:43
10:47
#21012
Finish
26.22 mi15:04:354:04:399:209:33
9:22
#21000
Faster pace
Steady pace
Slower pace

Checkpoint and Segment Rankings

CheckpointDistanceSeg. DistOverallFemalesF45-49Seg. OverallSeg. FemalesSeg. F45-49
5K3.11 mi3.11 mi141574013401317716(Top 62%)6154(Top 50%)6154(Top 339%)
10K6.21 mi3.10 mi15677-15204944-9314944-93117070(Top 60%)5748(Top 47%)5748(Top 317%)
15K9.32 mi3.11 mi16450-7735409-4655409-46517716(Top 62%)6154(Top 50%)6154(Top 339%)
20K12.43 mi3.11 mi18092-16426391-9826391-98221953(Top 77%)8556(Top 70%)8556(Top 472%)
Half13.11 mi0.68 mi18295-2036515-1246515-12421600(Top 76%)8369(Top 68%)8369(Top 462%)
25K15.53 mi2.42 mi19200-9057026-5117026-51122314(Top 79%)8822(Top 72%)8822(Top 487%)
30K18.64 mi3.11 mi20342-11427724-6987724-69823201(Top 82%)9437(Top 77%)9437(Top 521%)
20M20.00 mi1.36 mi20764-4227977-2537977-25323747(Top 84%)9814(Top 80%)9814(Top 541%)
21M21.00 mi1.00 mi21065-3018159-1828159-18223771(Top 84%)9898(Top 81%)9898(Top 546%)
35K21.75 mi0.75 mi21063+28169-108169-1021207(Top 75%)8615(Top 70%)8615(Top 475%)
23M23.00 mi1.25 mi21148-858242-738242-7322264(Top 78%)9206(Top 75%)9206(Top 508%)
24M24.00 mi1.00 mi21094+548246-48246-419814(Top 70%)7989(Top 65%)7989(Top 441%)
40K24.85 mi0.85 mi21046+488226+208226+2019653(Top 69%)7974(Top 65%)7974(Top 440%)
25.2M25.20 mi0.35 mi21012+348219+78219+719996(Top 70%)8157(Top 67%)8157(Top 450%)
Finish26.22 mi1.02 mi21000+128224-58224-520689(Top 73%)8494(Top 69%)8494(Top 469%)

Segment Performance Analysis

10K→15K

0.0 - 3.1 mi

Top 62%
×21story building
+97ft-345ft

Overall

17716

Females

6154

F45-49

6154

5K→10K

3.1 - 6.2 mi

Top 60%
×5story building
+79ft-138ft

Overall

17070

Females

5748

F45-49

5748

10K→15K

6.2 - 9.3 mi

Top 62%
×3story building
+67ft-78ft

Overall

17716

Females

6154

F45-49

6154

15K→20K

9.3 - 12.4 mi

Top 77%
×5story building
+106ft-86ft

Overall

21953

Females

8556

F45-49

8556

20K→Half

12.4 - 13.1 mi

Top 76%
×2story building
+19ft-37ft

Overall

21600

Females

8369

F45-49

8369

Half→25K

13.1 - 15.5 mi

Top 79%
×4story building
+66ft-88ft

Overall

22314

Females

8822

F45-49

8822

25K→30K

15.5 - 18.6 mi

Top 82%
×9story building
+181ft-148ft

Overall

23201

Females

9437

F45-49

9437

30K→20M

18.6 - 20.0 mi

Top 84%
×5story building
+64ft-50ft

Overall

23747

Females

9814

F45-49

9814

20M→21M

20.0 - 21.0 mi

Top 84%
×8story building
+106ft-24ft

Overall

23771

Females

9898

F45-49

9898

21M→35K

21.0 - 21.8 mi

Top 75%
×7story building
+17ft-86ft

Overall

21207

Females

8615

F45-49

8615

35K→23M

21.8 - 23.0 mi

Top 78%
×5story building
+23ft-63ft

Overall

22264

Females

9206

F45-49

9206

23M→24M

23.0 - 24.0 mi

Top 70%
×6story building
+12ft-82ft

Overall

19814

Females

7989

F45-49

7989

24M→40K

24.0 - 24.9 mi

Top 69%
×1story
+6ft-20ft

Overall

19653

Females

7974

F45-49

7974

40K→25.2M

24.9 - 25.2 mi

Top 70%
×1story
+13ft-16ft

Overall

19996

Females

8157

F45-49

8157

25.2M→Finish

25.2 - 26.2 mi

Top 73%
×2story building
+22ft-21ft

Overall

20689

Females

8494

F45-49

8494

Passing Analysis

Category:
Athletes Passed
626
Passed By
7469
Net Change
-6843
SegmentAthletes PassedPassed ByNet ChangeStart RankEnd Rank
Start → 5K----#14157
5K → 10K341554-1520#14157#15677
10K → 15K49822-773#15677#16450
15K → 20K191661-1642#16450#18092
20K → Half9212-203#18092#18295
Half → 25K33938-905#18295#19200
25K → 30K361178-1142#19200#20342
30K → 20M26448-422#20342#20764
20M → 21M32333-301#20764#21065
21M → 35K6260+2#21065#21063
35K → 23M62147-85#21063#21148
23M → 24M9036+54#21148#21094
24M → 40K7022+48#21094#21046
40K → 25.2M4713+34#21046#21012
25.2M → Finish5745+12#21012#21000
TOTALS6267469-6843
📊

Passing Visuals

Category:
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

Public Race Data

Boston Athletic Association

Boston Athletic Association

Mika Timing

Mika Timing