J.J. Wolf vs Stefan KozlovPrediction, Head-to-Head Results, and Stats
J.J. Wolf and Stefan Kozlov have met 9 times since 2019; J.J. Wolf leads 5–4. Their first meeting came at Columbus in 2019 on hard. On hard courts Wolf leads 5–4. 1 of their meetings has been a final, with Wolf leading those 1–0. Across all meetings Wolf has taken 12 sets to Kozlov's 8. Their most recent meeting: J.J. Wolf won at Cleveland Challenger (2025).
Spread & Straight-Sets Form
Completed best-of-3 matches · Last 12 months
| Indicator | Wolf | Kozlov | ||
|---|---|---|---|---|
| Indicator | J.J. Wolf | Stefan Kozlov | ||
| Wins in straight sets | 70% | 16/23 | 56% | 15/27 |
| Wins a set when losing | 43% | 3/7 | 52% | 11/21 |
| Goes to a deciding set | 33% | 10/30 | 48% | 23/48 |
| Covers −1.5 sets as favorite | 55% | 12/22 | 46% | 13/28 |
| Covers +1.5 sets as underdog | 80% | 4/5 | 76% | 13/17 |
| Tiebreak sets won | 60% | 6/10 | 47% | 7/15 |
| Wins after taking set 1 | 95% | 18/19 | 87% | 26/30 |
| Wins 2-0 after taking set 1 | 84% | 16/19 | 50% | 15/30 |
Colored rows are higher-is-better: green above 50%, red below. Favorite/underdog set by book odds; cover rows count only matches with odds on record. Head-to-head: 7 of 9 completed meetings ended in straight sets (Wolf 5, Kozlov 2).
Style Matchup
Playing styles and historical archetype record
Wolf
👑 The Complete Package
Kozlov
🪃 Counterpuncher
Matchup analysis
The 👑 The Complete Package archetype wins about 56% vs 🪃 Counterpuncher across 458 matches in our dataset: a stylistic lean toward J.J. Wolf.
The Complete Package players often use elite serve & return and high bp conversion to pressure the counterpuncher's elite bp conversion.
Previous meetings
9 career meetings, newest first
Jan 31, 2025
Cleveland Challenger
H Hard · Quarterfinals
Jul 5, 2024
Bloomfield Hills Challenger
H Hard · Quarterfinals
Sep 19, 2022
San Diego Open - San Diego
H Hard · 1st Round
Nov 20, 2021
Champaign Challenger
H Hard · Semifinals
Nov 6, 2021
Charlottesville Challenger
H Hard · Semifinals
Oct 31, 2021
Las Vegas Challenger
H Hard · Final
Sep 25, 2021
Columbus Challenger
H Hard · Semifinals
Nov 12, 2019
Champaign
H Hard · Quarterfinals
Jan 8, 2019
Columbus
H Hard · Round of 64
Prop Research
Hit rates on common betting markets · Last 90 days
| Outcome | Wolf | Kozlov | ||
|---|---|---|---|---|
| Outcome | J.J. Wolf | Stefan Kozlov | ||
| 1 or more | 100% | 16/16 | 83% | 5/6 |
| 3 or more | 100% | 16/16 | 50% | 3/6 |
| 5 or more | 75% | 12/16 | 0% | 0/6 |
| 10 or more | 19% | 3/16 | 0% | 0/6 |
| 15 or more | 0% | 0/16 | 0% | 0/6 |
| 20 or more | 0% | 0/16 | 0% | 0/6 |
Player ROI
Hypothetical if you put 1u on each player to win every one of their matches · Last 90 days
| Metric | Wolf | Kozlov |
|---|---|---|
| W-L | 12–4 | 3–4 |
| Avg odds | 1.62 | 2.54 |
| ROI % | +16.4% | +13.0% |
| Units P/L | +2.63u | +0.91u |
Small sample: ROI stabilizes with more matches; fewer than 10 in the window is noisy.
Travel
Last 30 days
| Metric | Wolf | Kozlov |
|---|---|---|
| Countries | 2 | 1 |
| Events | 2 | 1 |
| Matches | 4 | 2 |
| Distance | 2,012 mi · 3,238 km | 0 mi · 0 km |
| Route | CAN → USA | USA |
Host country from the tournament each match was played in, over the last 30 days. Route is the order of countries visited; consecutive stops in the same country are shown once. Distance is the great-circle total between host cities, shown only when every stop in the window is geocoded. A rough fatigue signal, not a headline stat.
Common opponents
Results vs. opponents both players faced · Last 12 months
Across 7 shared opponents, both Wolf and Kozlov posted a 43% win rate.
| Opponent | Wolf | Kozlov |
|---|---|---|
| James Duckworth | L 57 67 | L 36 26 |
| Tyler Zink | W 63 63 | W 64 61 |
| Jacob Fearnley | L 67 64 36 | L 63 36 26 |
| Jay Friend | L 75 67 36 | L 26 64 36 |
| Andres Martin | W 36 63 64 | L 26 26 |
| Raphael Perot | W 63 62 | W 63 61 |
| Daniil Glinka | L 36 67 | W 62 63 |
Recent Form
Last five matches per player
James Duckworth
Cincinnati Open - Cincinnati · 1st Round
Aug 14
Mark Lajal
Vancouver Challenger · Final
Aug 1
Jay Dylan Hara Friend
Vancouver Challenger · Semifinals
Jul 31
Hayato Matsuoka
Vancouver Challenger · Quarterfinals
Jul 31
Tyler Zink
Vancouver Challenger · 2nd Round
Jul 30
Zhizhen Zhang
Vancouver Challenger · 1st Round
Jul 29
Jacob Fearnley
Bloomfield Hills Challenger · Quarterfinals
Jul 24
Coleman Wong
Bloomfield Hills Challenger · 2nd Round
Jul 23
Harry Wendelken
Brownsburg Challenger · 2nd Round
Aug 13
Aidan Mayo
Brownsburg Challenger · 1st Round
Aug 12
Alan Magadan
Bloomfield Hills Challenger · 1st Round
Jul 21
Yi Zhou
Pozoblanco Challenger · 1st Round
Jul 14
Tommaso Compagnucci
Bundesliga - men
Jul 12
Jacob Fearnley
Newport Challenger · 2nd Round
Jul 10
Yibing Wu
Newport Challenger · 1st Round
Jul 9
Garrett Johns
Newport challenger
Jul 7
Rivalry momentum
Cumulative head-to-head lead over time
Win rate
Matches, sets and games won · Last 12 months · 30–48 matches
| Metric | Wolf | Kozlov |
|---|---|---|
| Matches won | 77% | 56% |
| Sets won | 70% | 55% |
| Games won | 57% | 52% |
Record by tier
Head-to-head record by tournament tier
| Stage | Wolf | Kozlov |
|---|---|---|
| Finals | 1 | 0 |
| ATP Challenger Tour | 4 | 4 |
| ATP World Tour 250 | 1 | 0 |
By surface
Head-to-head record per surface
| Surface | Wolf | Kozlov |
|---|---|---|
| Hard | 5 | 4 |
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