H2H data updated: 2026-09-04 00:00 UTC

Stefan Kozlov vs Thai-Son Kwiatkowski

Compare the head-to-head record, career totals, season-by-season performance, and match log for Stefan Kozlov vs Thai-Son Kwiatkowski.

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Stefan Kozlov
United States Age 28 Right-Handed 183 cm / 6'0"
H2H
0 – 0
0 main draw meetings
Thai-Son Kwiatkowski
USA Age 31 Right-Handed 188 cm / 6'2"

H2H Match Log

PlayerScorePlayerMatch DataDateRoundTournamentCategorySurface
Stefan Kozlov #224 6-3 6-4 Thai-Son Kwiatkowski #1279 Match data Feb 6, 2023 Q1 Q Dallas Open ATP 250 Hard

1 qualifying meeting shown in the table; qualifying is excluded from the H2H score. Arrows show an edition's recorded category and documented modern equivalent; unresolved editions keep their recorded category. Asterisked totals include editions mapped from documented historical predecessor categories. Mapping details.

Career Comparison

Player Current Peak Pts Elo W L Win % GS 1000 including documented historical predecessor categories Finals 500 including documented historical predecessor categories 250 including documented historical predecessor categories Titles
Stefan Kozlov #297 #103 558 1,673 9 26 25.7% 0 0 0 0 0 0
Thai-Son Kwiatkowski #1,378 #181 314 1,529 0 7 0.0% 0 0 0 0 0 0

Career Progression by Age

Seasons are aligned by the age each player spent most of that calendar year. GS and Titles are cumulative career totals through that season.

Age Stefan Kozlov Thai-Son Kwiatkowski
YrW-LWin %RankEloGSTitles YrW-LWin %RankEloGSTitles
15 2013 0–1 0.0% #1083 1,489 0 0 — — — — — — —
16 2014 0–1 0.0% #467 1,453 0 0 — — — — — — —
17 2015 0–2 0.0% #351 1,420 0 0 — — — — — — —
18 2016 3–2 60.0% #116 1,481 0 0 — — — — — — —
19 2017 2–9 18.2% #167 1,549 0 0 — — — — — — —
20 2018 0–1 0.0% #316 1,528 0 0 — — — — — — —
22 2020 0–1 0.0% #371 1,514 0 0 2017 0–2 0.0% #520 1,477 0 0
23 2021 0–1 0.0% #159 1,550 0 0 2018 0–1 0.0% #296 1,503 0 0
24 2022 4–8 33.3% #198 1,529 0 0 2019 0–1 0.0% #243 1,511 0 0
25 — — — — — — — 2020 0–1 0.0% #212 1,469 0 0
26 — — — — — — — 2021 0–1 0.0% #221 1,455 0 0
28 — — — — — — — 2023 0–1 0.0% #322 1,450 0 0

Surface Results by Age

Seasons are aligned by the age each player spent most of that calendar year. Results cover completed main-draw matches. Bold green marks the higher win percentage when both players have at least 5 matches on that surface at the aligned age.

Age Stefan Kozlov Thai-Son Kwiatkowski
Yr HardClayGrass Yr HardClayGrass
W L M Win % W L M Win % W L M Win % W L M Win % W L M Win % W L M Win %
15 2013 — — — — — — — — 0 1 1 0.0% — — — — — — — — — — — — —
16 2014 0 1 1 0.0% — — — — — — — — — — — — — — — — — — — — —
17 2015 0 2 2 0.0% — — — — — — — — — — — — — — — — — — — — —
18 2016 — — — — — — — — 3 2 5 60.0% — — — — — — — — — — — — —
19 2017 0 6 6 0.0% — — — — 2 3 5 40.0% — — — — — — — — — — — — —
20 2018 — — — — 0 1 1 0.0% — — — — — — — — — — — — — — — — —
22 2020 0 1 1 0.0% — — — — — — — — 2017 0 1 1 0.0% — — — — 0 1 1 0.0%
23 2021 0 1 1 0.0% — — — — — — — — 2018 0 1 1 0.0% — — — — — — — —
24 2022 4 6 10 40.0% — — — — 0 2 2 0.0% 2019 0 1 1 0.0% — — — — — — — —
25 — — — — — — — — — — — — — 2020 0 1 1 0.0% — — — — — — — —
26 — — — — — — — — — — — — — 2021 0 1 1 0.0% — — — — — — — —
28 — — — — — — — — — — — — — 2023 0 1 1 0.0% — — — — — — — —
Career — 4 17 21 19.0% 0 1 1 0.0% 5 8 13 38.5% — 0 6 6 0.0% — — — — 0 1 1 0.0%

Performance Progression by Age

Seasons are aligned by the age each player spent most of that calendar year. Sample is shown as matches with detailed serve and return statistics / total main draw matches. Bold green marks the stronger value when both stat samples contain at least 5 matches; lower is better for DFs/M.

Age Stefan Kozlov Thai-Son Kwiatkowski
Yr Sample Aces/M DFs/M 1st Sv% 1st Pts% 2nd Pts% BP Saved% BP Conv% Svc Pts% Ret Pts% Yr Sample Aces/M DFs/M 1st Sv% 1st Pts% 2nd Pts% BP Saved% BP Conv% Svc Pts% Ret Pts%
15 2013 1/1 4.0 3.0 43.5% 74.5% 42.6% 62.5% 44.4% 56.5% 36.0% — —/— — — — — — — — — —
16 2014 1/1 2.0 4.0 56.4% 61.3% 50.0% 63.6% 16.7% 56.4% 35.5% — —/— — — — — — — — — —
17 2015 2/2 0.5 3.0 44.3% 48.1% 35.6% 27.8% 67.5% 41.3% 42.2% — —/— — — — — — — — — —
18 2016 5/5 4.2 4.8 55.8% 67.8% 41.9% 67.2% 40.4% 56.9% 38.4% — —/— — — — — — — — — —
19 2017 11/11 3.6 4.1 58.0% 65.2% 44.1% 53.2% 35.0% 56.5% 32.9% — —/— — — — — — — — — —
20 2018 1/1 2.0 5.0 50.9% 65.5% 35.7% 20.0% 50.0% 50.9% 28.0% — —/— — — — — — — — — —
22 2020 1/1 1.0 5.0 68.5% 54.1% 57.1% 36.4% 50.0% 55.1% 31.7% 2017 2/2 5.0 7.0 60.7% 62.6% 45.5% 42.5% 59.7% 55.6% 34.9%
23 2021 1/1 1.0 1.0 76.4% 54.8% 61.5% 42.9% 25.0% 56.4% 32.7% 2018 1/1 12.0 1.0 72.6% 68.9% 41.2% 60.0% 0.0% 61.3% 19.0%
24 2022 12/12 1.6 4.8 72.4% 60.0% 43.6% 59.6% 35.7% 55.2% 36.0% 2019 1/1 9.0 7.0 58.4% 73.3% 40.6% 40.0% 33.3% 59.7% 33.8%
25 — —/— — — — — — — — — — 2020 1/1 11.0 4.0 57.9% 64.3% 49.0% 25.0% 28.6% 57.9% 29.2%
26 — —/— — — — — — — — — — 2021 1/1 8.0 3.0 57.4% 66.7% 45.0% 42.9% 60.0% 57.4% 37.2%
28 — —/— — — — — — — — — — 2023 1/1 1.0 4.0 51.8% 63.6% 51.2% 28.6% 33.3% 57.6% 30.9%
Career — 35/35 2.6 4.3 62.0% 62.4% 43.9% 54.8% 38.2% 55.1% 35.3% — 7/7 7.3 4.7 59.9% 66.0% 45.4% 40.2% 39.2% 57.9% 31.4%

Advanced Statistics Comparison by Age

Seasons are aligned by the age each player spent most of that calendar year. Metrics are precomputed from eligible main-draw results; point-stat values use the available detailed sample. Bold green marks the stronger value when both underlying samples are sufficient. Lower is better for Schedule because a negative value means a tougher schedule. Career Schedule is normalized per 100 matches.

Age Stefan Kozlov Thai-Son Kwiatkowski
Yr Elo P+ Serve+ Return+ PD TPW% Hard Elo Clay Elo Grass Elo Set Win % Set Margin Dec. Set Tiebreak Pressure+ Schedule Yr Elo P+ Serve+ Return+ PD TPW% Hard Elo Clay Elo Grass Elo Set Win % Set Margin Dec. Set Tiebreak Pressure+ Schedule
15 2013 1490 100.2 -4.35 +1.56 0.828 46.1% — — — 33.3% -1.33 0–1 1–0 — +0.13 — — — — — — — — — — — — — — — —
16 2014 1454 100.0 +0.67 0.00 0.813 45.3% — — — 0.0% -3.00 — — — -0.04 — — — — — — — — — — — — — — — —
17 2015 1420 101.3 -5.76 -0.97 0.718 41.8% — — — 0.0% -3.50 — — — +0.21 — — — — — — — — — — — — — — — —
18 2016 1481 107.5 -3.43 +1.33 0.891 48.1% — — +119 54.5% +0.09 1–0 — — -0.03 — — — — — — — — — — — — — — — —
19 2017 1550 118.7 -5.47 -0.25 0.757 44.9% -74 — +123 21.7% -1.70 2–1 (67%) 0–3 (0%) — +0.21 — — — — — — — — — — — — — — — —
20 2018 1528 106.2 +0.19 -0.20 0.570 40.2% — — — 0.0% -3.50 — — — -0.08 — — — — — — — — — — — — — — — —
21 2019 1514 100.9 — — — — — — — — — — — — — 2016 1488 100.1 — — — — — — — — — — — — —
22 2020 1514 104.1 -1.24 +2.90 0.705 43.9% — — — 33.3% -2.33 0–1 1–0 — -0.06 2017 1478 106.9 -2.01 0.00 0.786 45.3% — — — 28.6% -1.14 0–1 0–1 — -0.10
23 2021 1550 110.6 +2.69 +0.42 0.749 44.9% — — — 0.0% -3.00 — — — +0.04 2018 1503 106.9 -2.53 -3.20 0.490 40.8% — — — 0.0% -2.50 — — — +0.10
24 2022 1530 118.4 -4.38 +0.86 0.803 45.9% +20 — — 32.3% -1.48 2–0 1–1 — -0.54 2019 1512 112.6 -5.09 +4.02 0.840 47.3% — — — 0.0% -2.00 — — — -0.21
25 2023 1458 91.9 — — — — — — — — — — — — — 2020 1470 101.6 -0.62 -0.15 0.694 44.5% — — — 25.0% -1.75 — 0–1 — 0.00
26 2024 1433 92.7 — — — — — — — — — — — — — 2021 1456 107.9 -0.38 -0.59 0.875 47.3% — — — 33.3% -1.00 0–1 — — +0.06
27 2025 1436 101.4 — — — — — — — — — — — — — 2022 1422 95.8 — — — — — — — — — — — — —
28 2026 1418 97.5 — — — — — — — — — — — — — 2023 1450 111.9 -0.73 -3.36 0.729 45.8% — — — 33.3% -1.33 0–1 — — +0.10
29 — — — — — — — — — — — — — — — — 2024 1421 98.7 — — — — — — — — — — — — —
30 — — — — — — — — — — — — — — — — 2025 1395 96.8 — — — — — — — — — — — — —
31 — — — — — — — — — — — — — — — — 2026 1386 95.8 — — — — — — — — — — — — —
Career — 1674 113.0 -4.10 +0.48 0.784 45.4% -15 — +121 28.4% -1.58 5–3 (63%) 3–4 (43%) 104.8 -0.46 — 1530 109.5 -1.91 -0.47 0.746 45.2% — — — 23.8% -1.47 0–3 (0%) 0–2 — -0.71

Career Rivalries

Each player's five most-played main-draw opponents. The current matchup is highlighted when it appears in a player's top five.