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BOSTON MARATHON 2025

Ron Kozlin

Bib: 25996•M

SC

0:00
0:00
/ mi
Masters
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Overall
#0 / 28404
Gender (Male)
#0 / 16105
Masters (Masters Men)
#0 / 10463
Division (M55-59)
#0 / 1648
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
9:18/mi
28:55
↑ 97↓ 3451.5%
10K· 6.21 mi
9:12/mi
57:31
↑ 79↓ 1380.4%
15K· 9.32 mi
9:18/mi
1:26:25
↑ 67↓ 78
20K· 12.43 mi
9:33/mi
1:56:06
↑ 106↓ 860.1%
Half· 13.11 mi
9:21/mi
2:02:29
↑ 19↓ 370.5%
25K· 15.53 mi
9:59/mi
2:26:41
↑ 66↓ 880.2%
30K· 18.64 mi
11:10/mi
3:01:23
↑ 181↓ 1480.2%
20M
12:13/mi
3:17:59
↑ 64↓ 500.2%
21M
11:56/mi
3:29:55
↑ 106↓ 241.6%
35K· 21.75 mi
12:54/mi
3:39:34
↑ 17↓ 861.7%
23M
11:16/mi
3:53:40
↑ 23↓ 630.6%
24M
10:51/mi
4:04:31
↓ 821.3%
40K· 24.85 mi
11:00/mi
4:13:55
↓ 200.3%
25.2M
12:51/mi
4:18:21
↑ 13↓ 160.2%
Finish· 26.22 mi
10:03/mi
4:28:35
↑ 22↓ 21

The Course

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Half Splits

1st Half· via HalfFaster
Distance13.11 mi
Time2:02:29
Pace9:21 /mi
2nd Half
Distance13.11 mi
Time2:26:06
Pace11:09 /mi
📊Positive Split: 19.3% slower second half

Checkpoint Splits

CheckpointDistanceTime of DayTimeAvg PaceSegment TimeSegment PaceDiff
5K
3.11 mi11:47:3928:559:1828:55
9:18
-
10K
6.21 mi12:16:1557:319:1528:36
9:12
-0:06
15K
9.32 mi12:45:091:26:259:1628:54
9:18
+0:06
20K
12.43 mi13:14:501:56:069:2129:41
9:33
+0:15
Half
13.11 mi13:21:132:02:299:216:23
9:21
-0:12
25K
15.53 mi13:45:252:26:419:2724:12
9:59
+0:38
30K
18.64 mi14:20:073:01:239:4434:42
11:10
+1:11
20M
20.00 mi14:36:433:17:599:5416:36
12:13
+1:03
21M
21.00 mi14:48:393:29:5510:0011:56
11:56
-0:17
35K
21.75 mi14:58:183:39:3410:069:39
12:54
+0:58
23M
23.00 mi15:12:243:53:4010:1014:06
11:16
-1:38
24M
24.00 mi15:23:154:04:3110:1110:51
10:51
-0:25
40K
24.85 mi15:32:394:13:5510:139:24
11:00
+0:09
25.2M
25.20 mi15:37:054:18:2110:154:26
12:51
+1:51
Finish
26.22 mi15:47:194:28:3510:1510:14
10:03
-2:48

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

9:12 /mi

Average Pace

10:15 /mi

Slowest Pace

12:54 /mi

Loading chart...
Fastest
Middle
Slowest
Average

📊Segments

Segment Time Comparison

Time at Faster Pace

2:36:55

58% of race

Time at Steady Pace

1:09:03

26% of race

Time at Slower Pace

42:37

16% of race

Average Pace: 10:15 /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 mi11:47:3928:559:1828:55
9:18
#23580
10K
6.21 mi12:16:1557:319:1528:36
9:12
#23403
15K
9.32 mi12:45:091:26:259:1628:54
9:18
#23346
20K
12.43 mi13:14:501:56:069:2129:41
9:33
#23261
Half
13.11 mi13:21:132:02:299:216:23
9:21
#23262
25K
15.53 mi13:45:252:26:419:2724:12
9:59
#23249
30K
18.64 mi14:20:073:01:239:4434:42
11:10
#23482
20M
20.00 mi14:36:433:17:599:5416:36
12:13
#23727
21M
21.00 mi14:48:393:29:5510:0011:56
11:56
#23719
35K
21.75 mi14:58:183:39:3410:069:39
12:54
#23907
23M
23.00 mi15:12:243:53:4010:1014:06
11:16
#23894
24M
24.00 mi15:23:154:04:3110:1110:51
10:51
#23881
40K
24.85 mi15:32:394:13:5510:139:24
11:00
#23855
25.2M
25.20 mi15:37:054:18:2110:154:26
12:51
#23889
Finish
26.22 mi15:47:194:28:3510:1510:14
10:03
#23871
Faster pace
Steady pace
Slower pace

Checkpoint and Segment Rankings

CheckpointDistanceSeg. DistOverallMalesM55-59Seg. OverallSeg. MalesSeg. M55-59
5K3.11 mi3.11 mi23580140381403823215(Top 82%)13939(Top 87%)13939(Top 846%)
10K6.21 mi3.10 mi23403+17713972+6613972+6623216(Top 82%)13909(Top 86%)13909(Top 844%)
15K9.32 mi3.11 mi23346+5713967+513967+523215(Top 82%)13939(Top 87%)13939(Top 846%)
20K12.43 mi3.11 mi23261+8513936+3113936+3123069(Top 81%)13822(Top 86%)13822(Top 839%)
Half13.11 mi0.68 mi23262-113933+313933+323131(Top 81%)13850(Top 86%)13850(Top 840%)
25K15.53 mi2.42 mi23249+1313922+1113922+1123213(Top 82%)13845(Top 86%)13845(Top 840%)
30K18.64 mi3.11 mi23482-23313973-5113973-5124321(Top 86%)14222(Top 88%)14222(Top 863%)
20M20.00 mi1.36 mi23727-24514055-8214055-8225553(Top 90%)14708(Top 91%)14708(Top 892%)
21M21.00 mi1.00 mi23719+814040+1514040+1523480(Top 83%)13669(Top 85%)13669(Top 829%)
35K21.75 mi0.75 mi23907-18814118-7814118-7826867(Top 95%)15273(Top 95%)15273(Top 927%)
23M23.00 mi1.25 mi23894+1314083+3514083+3523803(Top 84%)13737(Top 85%)13737(Top 834%)
24M24.00 mi1.00 mi23881+1314072+1114072+1123671(Top 83%)13649(Top 85%)13649(Top 828%)
40K24.85 mi0.85 mi23855+2614047+2514047+2523134(Top 81%)13306(Top 83%)13306(Top 807%)
25.2M25.20 mi0.35 mi23889-3414059-1214059-1224817(Top 87%)14166(Top 88%)14166(Top 860%)
Finish26.22 mi1.02 mi23871+1814040+1914040+1923060(Top 81%)13311(Top 83%)13311(Top 808%)

Segment Performance Analysis

10K→15K

0.0 - 3.1 mi

Top 82%
×21story building
+97ft-345ft

Overall

23215

Males

13939

M55-59

13939

5K→10K

3.1 - 6.2 mi

Top 82%
×5story building
+79ft-138ft

Overall

23216

Males

13909

M55-59

13909

10K→15K

6.2 - 9.3 mi

Top 82%
×3story building
+67ft-78ft

Overall

23215

Males

13939

M55-59

13939

15K→20K

9.3 - 12.4 mi

Top 81%
×5story building
+106ft-86ft

Overall

23069

Males

13822

M55-59

13822

20K→Half

12.4 - 13.1 mi

Top 81%
×2story building
+19ft-37ft

Overall

23131

Males

13850

M55-59

13850

Half→25K

13.1 - 15.5 mi

Top 82%
×4story building
+66ft-88ft

Overall

23213

Males

13845

M55-59

13845

25K→30K

15.5 - 18.6 mi

Top 86%
×9story building
+181ft-148ft

Overall

24321

Males

14222

M55-59

14222

30K→20M

18.6 - 20.0 mi

Top 90%
×5story building
+64ft-50ft

Overall

25553

Males

14708

M55-59

14708

20M→21M

20.0 - 21.0 mi

Top 83%
×8story building
+106ft-24ft

Overall

23480

Males

13669

M55-59

13669

21M→35K

21.0 - 21.8 mi

Top 95%
×7story building
+17ft-86ft

Overall

26867

Males

15273

M55-59

15273

35K→23M

21.8 - 23.0 mi

Top 84%
×5story building
+23ft-63ft

Overall

23803

Males

13737

M55-59

13737

23M→24M

23.0 - 24.0 mi

Top 83%
×6story building
+12ft-82ft

Overall

23671

Males

13649

M55-59

13649

24M→40K

24.0 - 24.9 mi

Top 81%
×1story
+6ft-20ft

Overall

23134

Males

13306

M55-59

13306

40K→25.2M

24.9 - 25.2 mi

Top 87%
×1story
+13ft-16ft

Overall

24817

Males

14166

M55-59

14166

25.2M→Finish

25.2 - 26.2 mi

Top 81%
×2story building
+22ft-21ft

Overall

23060

Males

13311

M55-59

13311

Passing Analysis

Category:
Athletes Passed
1320
Passed By
1611
Net Change
-291
SegmentAthletes PassedPassed ByNet ChangeStart RankEnd Rank
Start → 5K----#23580
5K → 10K330153+177#23580#23403
10K → 15K205148+57#23403#23346
15K → 20K188103+85#23346#23261
20K → Half3132-1#23261#23262
Half → 25K133120+13#23262#23249
25K → 30K94327-233#23249#23482
30K → 20M27272-245#23482#23727
20M → 21M7466+8#23727#23719
21M → 35K8196-188#23719#23907
35K → 23M6754+13#23907#23894
23M → 24M4734+13#23894#23881
24M → 40K5630+26#23881#23855
40K → 25.2M943-34#23855#23889
25.2M → Finish5133+18#23889#23871
TOTALS13201611-291
📊

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