Boston Marathon logo
BOSTON MARATHON 2023

Brian Chakulski

Bib: 9356•M

CT

0:00
0:00
/ mi
Masters
Be the first to cheer!
Overall
#0 / 26622
Top 35%
Gender (Male)
#0 / 15176
Top 50%
Masters (Masters Men)
#0 / 9891
Top 39%
Division (M40-44)
#0 / 2241
Race Day Weather
49°/39°F
light intensity drizzle

⏱️ Race Timeline

Start
0:00:00
Race begins
5K· 3.11 mi
23:17
Rank: #9565
Start → 5K
23:17 | 7:30/mi
10K· 6.21 mi
46:36
Rank: #10014 (-449)
5K → 10K
23:19 | 7:30/mi
15K· 9.32 mi
1:10:08
Rank: #10271 (-257)
10K → 15K
23:32 | 7:34/mi
20K· 12.43 mi
1:33:45
Rank: #10226 (+45)
15K → 20K
23:37 | 7:36/mi
Half· 13.11 mi
1:38:50
Rank: #10184 (+42)
20K → Half
5:05 | 7:27/mi
25K· 15.53 mi
1:57:26
Rank: #10132 (+52)
Half → 25K
18:36 | 7:40/mi
30K· 18.64 mi
2:21:56
Rank: #10079 (+53)
25K → 30K
24:30 | 7:53/mi
20M
2:32:35
Rank: #9971 (+108)
30K → 20M
10:39 | 7:50/mi
21M
2:40:47
Rank: #9857 (+114)
20M → 21M
8:12 | 8:12/mi
35K· 21.75 mi
2:46:33
Rank: #9856 (+1)
21M → 35K
5:46 | 7:42/mi
23M
2:56:22
Rank: #9752 (+104)
35K → 23M
9:49 | 7:50/mi
24M
3:03:56
Rank: #9642 (+110)
23M → 24M
7:34 | 7:34/mi
40K· 24.85 mi
3:10:29
Rank: #9537 (+105)
24M → 40K
6:33 | 7:40/mi
25.2M
3:13:16
Rank: #9477 (+60)
40K → 25.2M
2:47 | 8:04/mi
Finish· 26.22 mi
3:20:46
Rank: #9389 (+88)
25.2M → Finish
7:30 | 7:22/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
Time1:38:50
Pace7:32 /mi
2nd Half
Distance13.11 mi
Time1:41:56
Pace7:47 /mi
📊Positive Split: 3.1% slower second half

Checkpoint Splits

CheckpointDistanceTime of DayTimeAvg PaceSegment TimeSegment PaceDiff
5K
3.11 mi10:49:1423:177:3023:17
7:30
-
10K
6.21 mi11:12:3346:367:3023:19
7:30
0:00
15K
9.32 mi11:36:051:10:087:3123:32
7:34
+0:04
20K
12.43 mi11:59:421:33:457:3323:37
7:36
+0:02
Half
13.11 mi12:04:471:38:507:325:05
7:27
-0:09
25K
15.53 mi12:23:231:57:267:3418:36
7:40
+0:13
30K
18.64 mi12:47:532:21:567:3724:30
7:53
+0:13
20M
20.00 mi12:58:322:32:357:3810:39
7:50
-0:03
21M
21.00 mi13:06:442:40:477:398:12
8:12
+0:22
35K
21.75 mi13:12:302:46:337:395:46
7:42
-0:30
23M
23.00 mi13:22:192:56:227:409:49
7:50
+0:08
24M
24.00 mi13:29:533:03:567:407:34
7:34
-0:16
40K
24.85 mi13:36:263:10:297:406:33
7:40
+0:06
25.2M
25.20 mi13:39:133:13:167:402:47
8:04
+0:24
Finish
26.22 mi13:46:433:20:467:407:30
7:22
-0:42

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

7:22 /mi

Average Pace

7:40 /mi

Slowest Pace

8:12 /mi

Loading chart...
Fastest
Middle
Slowest
Average

📊Segments

Segment Time Comparison

Time at Faster Pace

3:12:34

96% of race

Time at Steady Pace

8:12

4% of race

Time at Slower Pace

0:00

0% of race

Average Pace: 7:39 /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 mi10:49:1423:177:3023:17
7:30
#9565
10K
6.21 mi11:12:3346:367:3023:19
7:30
#10014
15K
9.32 mi11:36:051:10:087:3123:32
7:34
#10271
20K
12.43 mi11:59:421:33:457:3323:37
7:36
#10226
Half
13.11 mi12:04:471:38:507:325:05
7:27
#10184
25K
15.53 mi12:23:231:57:267:3418:36
7:40
#10132
30K
18.64 mi12:47:532:21:567:3724:30
7:53
#10079
20M
20.00 mi12:58:322:32:357:3810:39
7:50
#9971
21M
21.00 mi13:06:442:40:477:398:12
8:12
#9857
35K
21.75 mi13:12:302:46:337:395:46
7:42
#9856
23M
23.00 mi13:22:192:56:227:409:49
7:50
#9752
24M
24.00 mi13:29:533:03:567:407:34
7:34
#9642
40K
24.85 mi13:36:263:10:297:406:33
7:40
#9537
25.2M
25.20 mi13:39:133:13:167:402:47
8:04
#9477
Finish
26.22 mi13:46:433:20:467:407:30
7:22
#9389
Faster pace
Steady pace
Slower pace

Checkpoint and Segment Rankings

CheckpointDistanceSeg. DistOverallMalesM40-44Seg. OverallSeg. MalesSeg. M40-44
5K3.11 mi3.11 mi95657907790710785(Top 41%)8543(Top 56%)8543(Top 381%)
10K6.21 mi3.10 mi10014-4498154-2478154-24710471(Top 39%)8417(Top 55%)8417(Top 376%)
15K9.32 mi3.11 mi10271-2578313-1598313-15910785(Top 41%)8543(Top 56%)8543(Top 381%)
20K12.43 mi3.11 mi10226+458272+418272+4110089(Top 38%)8115(Top 53%)8115(Top 362%)
Half13.11 mi0.68 mi10184+428243+298243+299763(Top 37%)7956(Top 52%)7956(Top 355%)
25K15.53 mi2.42 mi10132+528200+438200+4310058(Top 38%)8016(Top 53%)8016(Top 358%)
30K18.64 mi3.11 mi10079+538137+638137+6310010(Top 38%)7829(Top 52%)7829(Top 349%)
20M20.00 mi1.36 mi9971+1088052+858052+859131(Top 34%)7269(Top 48%)7269(Top 324%)
21M21.00 mi1.00 mi9857+1147963+897963+898609(Top 32%)6845(Top 45%)6845(Top 305%)
35K21.75 mi0.75 mi9856+17946+177946+179949(Top 37%)7603(Top 50%)7603(Top 339%)
23M23.00 mi1.25 mi9752+1047852+947852+948673(Top 33%)6799(Top 45%)6799(Top 303%)
24M24.00 mi1.00 mi9642+1107769+837769+838153(Top 31%)6409(Top 42%)6409(Top 286%)
40K24.85 mi0.85 mi9537+1057682+877682+877701(Top 29%)6065(Top 40%)6065(Top 271%)
25.2M25.20 mi0.35 mi9477+607635+477635+476905(Top 26%)5537(Top 36%)5537(Top 247%)
Finish26.22 mi1.02 mi9389+887564+717564+717507(Top 28%)5874(Top 39%)5874(Top 262%)

Segment Performance Analysis

10K→15K

0.0 - 3.1 mi

Top 41%
×21stories
+97ft-345ft

Overall

10785

Males

8543

M40-44

8543

5K→10K

3.1 - 6.2 mi

Top 39%
×5stories
+79ft-138ft

Overall

10471

Males

8417

M40-44

8417

10K→15K

6.2 - 9.3 mi

Top 41%
×3stories
+67ft-78ft

Overall

10785

Males

8543

M40-44

8543

15K→20K

9.3 - 12.4 mi

Top 38%
×5stories
+106ft-86ft

Overall

10089

Males

8115

M40-44

8115

20K→Half

12.4 - 13.1 mi

Top 37%
×2stories
+19ft-37ft

Overall

9763

Males

7956

M40-44

7956

Half→25K

13.1 - 15.5 mi

Top 38%
×4stories
+66ft-88ft

Overall

10058

Males

8016

M40-44

8016

25K→30K

15.5 - 18.6 mi

Top 38%
×9stories
+181ft-148ft

Overall

10010

Males

7829

M40-44

7829

30K→20M

18.6 - 20.0 mi

Top 34%
×5stories
+64ft-50ft

Overall

9131

Males

7269

M40-44

7269

20M→21M

20.0 - 21.0 mi

Top 32%
×8stories
+106ft-24ft

Overall

8609

Males

6845

M40-44

6845

21M→35K

21.0 - 21.8 mi

Top 37%
×7stories
+17ft-86ft

Overall

9949

Males

7603

M40-44

7603

35K→23M

21.8 - 23.0 mi

Top 33%
×5stories
+23ft-63ft

Overall

8673

Males

6799

M40-44

6799

23M→24M

23.0 - 24.0 mi

Top 31%
×6stories
+12ft-82ft

Overall

8153

Males

6409

M40-44

6409

24M→40K

24.0 - 24.9 mi

Top 29%
×1story
+6ft-20ft

Overall

7701

Males

6065

M40-44

6065

40K→25.2M

24.9 - 25.2 mi

Top 26%
×1story
+13ft-16ft

Overall

6905

Males

5537

M40-44

5537

25.2M→Finish

25.2 - 26.2 mi

Top 28%
×2stories
+22ft-21ft

Overall

7507

Males

5874

M40-44

5874

Passing Analysis

Category:
Athletes Passed
1714*
Passed By
1535
Net Change
+176
SegmentAthletes PassedPassed ByNet ChangeStart RankEnd Rank
Start → 5K----#9565
5K → 10K143591-449#9565#10014
10K → 15K97353-257#10014#10271
15K → 20K177*132+45#10271#10226
20K → Half6018+42#10226#10184
Half → 25K153101+52#10184#10132
25K → 30K188*135+53#10132#10079
30K → 20M149*41+108#10079#9971
20M → 21M14530+114#9971#9857
21M → 35K4544+1#9857#9856
35K → 23M13834+104#9856#9752
23M → 24M12818+110#9752#9642
24M → 40K115*10+105#9642#9537
40K → 25.2M633+60#9537#9477
25.2M → Finish11325+88#9477#9389
TOTALS1714*1535+176

* Includes athletes who did not complete a segment (DNF/DNQ).

📊

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