RallyIQ

WTA · Right-handed · 18 charted matches · 2018–2026

Kaja Juvan

Archetype: Ad-court slider · Avoids the wide serve

Against an average opponent

Serve points won 59.5% ±3.0 raw 57.7% · tour 56.3% · 1,330 points
Return points won 43.1% ±3.1 raw 40.3% · tour 43.7% · 1,306 points

Serve and return points won, refitted against every opponent at once so a record built on weak or strong opposition is put on the same scale. Career, all surfaces, with a 90% margin. Raw is the plain share of points won.

Value per 100 shots

Direction choice −0.08 ±0.13 better than 40% of WTA · raw −0.07
Shot selection −0.23 ±0.22 better than 26% of WTA · raw −0.22
Execution −0.59 ±0.61 better than 30% of WTA · raw −0.54
Tactical adaptability −0.08 first serves toward what's working, set to set · 18 matches
Adaptation speed +0.04 same, every two to three service games · per 100 first serves
Points left on the table 2.80 per 100 shots vs best direction · lower than 24% of WTA

Points gained per 100 shots compared with an average tour player in the same position, adjusted for the strength of the opponents faced, with a 90% margin (shots clustered by match). Raw is before the opponent adjustment. Built on 7,144 shots.

Shot expected value

The share of points Kaja Juvan goes on to win after each option in the positions they face most often, shrunk toward tour average when the sample is small. Showing the 8 most-used options; teal marks the best one with at least 30 shots.

Rally, shots 5–8: drive to your backhand side

position worth 45% to the average player · 469 shots

OptionUsedWin %Tour
BH crosscourt 33% 48.6%±6.2 47.6%
BH through the middle 29% 37.6%±6.4 43.3%
BH down the line 10% 46.1%±9.9 46.8%
BH slice through the middle 6% 41.8%±11.5 34.4%
BH lob through the middle 5% 35.1%±11.8 27.1%
BH slice crosscourt 4% 37.1%±12.9 40.4%
FH inside-out 3% 57.4%±14.0 52.5%
BH slice down the line 3% 37.4%±13.9 31.7%

Rally, shots 5–8: drive to your forehand side

position worth 43% to the average player · 351 shots

OptionUsedWin %Tour
FH crosscourt 42% 41.6%±6.2 46.7%
FH through the middle 23% 42.8%±8.1 41.3%
FH down the line 19% 47.6%±8.9 44.9%
FH slice through the middle 5% 40.6%±12.9 29.2%
FH lob through the middle 5% 30.2%±12.6 29.4%

Rally, shots 5–8: drive to your middle

position worth 50% to the average player · 332 shots

OptionUsedWin %Tour
FH crosscourt 26% 48.6%±8.0 52.7%
FH down the line 20% 50.5%±8.8 52.2%
FH through the middle 18% 36.9%±8.9 45.8%
BH through the middle 14% 43.5%±10.1 46.2%
BH crosscourt 8% 47.1%±12.2 50.9%
BH down the line 6% 46.3%±12.8 50.0%

Serve +1: mid-depth return to your middle

position worth 51% to the average player · 210 shots

OptionUsedWin %Tour
FH crosscourt 31% 46.8%±8.9 54.0%
FH through the middle 17% 44.8%±10.9 45.5%
FH down the line 17% 46.7%±11.1 53.3%
BH through the middle 16% 43.9%±11.2 46.3%
BH crosscourt 9% 55.1%±13.1 52.5%

Serve under pressure

Pressure predictability index +2 How much less varied Kaja Juvan's first-serve direction gets on break points. Positive means easier to read. Based on 142 break-point first serves.

Deuce court

1st serveUsageBreak ptWon when in
Wide 30% 29% 64% / 66%
Body 21% 21% 62% / 57%
T 49% 50% 66% / 68%

659 normal · 34 break-point 1st serves

Ad court

1st serveUsageBreak ptWon when in
Wide 55% 57% 68% / 66%
Body 18% 19% 62% / 56%
T 27% 24% 59% / 64%

526 normal · 108 break-point 1st serves

Is the serve mix in equilibrium?

Game theory says a well-mixed server wins equally often with every direction they use. If one direction wins more, it's underused and points are being left behind. This is the minimax test Walker and Wooders ran on Wimbledon finals, applied to every charted first serve. Win rates include faults. "Optimal" allows for returners reading a habit. A direction loses 0.19 points per 100 serves for every 10 points of habitual usage, measured from WTA servers whose mix drifted between matches. Shifts stay within the range servers' habits actually vary, the only range that response was measured over.

Deuce court

1st serveUsagePoints wonOptimal
Wide30% 55.7%±5.3 n=207 45% ▲
Body21% 58.1%±6.1 n=145 6% ▼
T49% 56.1%±4.2 n=341 49%

Consistent with an optimal mix (p = 0.84).
Optimal mix: +0.3 per 100 first serves.

Ad court

1st serveUsagePoints wonOptimal
Wide55% 61.5%±4.1 n=350 70% ▲
Body18% 60.2%±6.7 n=116 6% ▼
T27% 54.5%±5.8 n=168 24% ▼

Consistent with an optimal mix (p = 0.18).
Optimal mix: +0.6 per 100 first serves.

Exploitability 0.43 points per 100 first serves What the optimal mix would win over the current one, both courts. More exploitable than 100% of WTA servers. Tested on matches they weren't fitted on, WTA mixes picked this way win 0.42 per 100 first serves on average.

Repeating the previous direction to the same court: +2.2±3.2 points per 100 against switching. Negative means returners read repeats. Tour-wide, repeating costs women about 0.4 points per 100 and costs men nothing, so men's returners don't measurably anticipate direction. (444 repeats, 847 switches.)

Return by serve direction

Return points won against each serve direction, compared with the tour average.

ServeCourtDirectionPointsWonvs tour
1stAd courtBody 106 43% −1.1±7.0
1stAd courtT 122 33% −2.2±6.3
1stAd courtWide 167 28% −6.9±5.2
1stDeuce courtBody 126 49% +6.6±6.6
1stDeuce courtT 167 31% −0.8±5.4
1stDeuce courtWide 135 27% −7.2±5.7
2ndAd courtBody 100 57% +1.5±7.2
2ndAd courtT 33 56% +1.3±10.3
2ndAd courtWide 97 48% −5.5±7.3
2ndDeuce courtBody 122 45% −9.5±6.6
2ndDeuce courtT 80 60% +3.8±7.7
2ndDeuce courtWide 49 52% −1.7±9.2

Signature patterns

Recurring sequences that win more than Kaja Juvan's own baseline, ranked by edge weighted by how often they're used.

Serve → +1

  1. Wide serve (ad court) → FH crosscourt used 4.9% · won 59% · −0.6±8.9 vs own baseline
  2. Body serve (ad court) → FH through the middle used 2.3% · won 55% · −4.4±11.1 vs own baseline
  3. T serve (deuce court) → BH crosscourt used 2.5% · won 55% · −4.6±10.9 vs own baseline
  4. Wide serve (ad court) → BH crosscourt used 2.2% · won 55% · −5.2±11.3 vs own baseline
  5. Wide serve (ad court) → BH down the line used 3.3% · won 55% · −4.5±10.1 vs own baseline

Return

  1. vs T serve (deuce court) → BH through the middle, deep used 5.5% · won 48% · +7.6±9.7 vs own baseline
  2. vs body serve (deuce court) → FH through the middle, deep used 3.8% · won 47% · +6.3±10.8 vs own baseline
  3. vs body serve (ad court) → BH through the middle, mid used 3.4% · won 46% · +5.2±11.1 vs own baseline
  4. vs body serve (deuce court) → FH through the middle, mid used 3.4% · won 46% · +5.2±11.1 vs own baseline
  5. vs body serve (deuce court) → FH crosscourt, mid used 3.2% · won 45% · +4.2±11.2 vs own baseline

Rally, consecutive own shots

  1. BH through the middle → FH through the middle used 3.1% · won 50% · +6.8±10.6 vs own baseline
  2. BH through the middle → FH down the line used 3.2% · won 47% · +4.3±10.5 vs own baseline
  3. FH down the line → FH crosscourt used 3.0% · won 47% · +4.2±10.7 vs own baseline
  4. FH crosscourt → FH down the line used 4.7% · won 46% · +2.8±9.3 vs own baseline
  5. BH crosscourt → BH down the line used 2.7% · won 46% · +3.2±11.0 vs own baseline

Discovered sequences

Mined from every me → opponent → me run of three shots, with no templates. Ranked by how much more often Kaja Juvan wins the point once the sequence happens, weighted by how often it happens. Think of them as chess openings.

  1. BH through the middle → FH through the middle → FH crosscourt used 0.6% · won 50% · +4.3±12.3 vs own baseline · +6.0 vs tour on the same sequence
  2. BH crosscourt → BH crosscourt → BH down the line used 0.6% · won 50% · +4.3±12.3 vs own baseline · +6.9 vs tour on the same sequence
  3. BH through the middle → BH crosscourt → BH crosscourt used 0.5% · won 50% · +4.2±12.9 vs own baseline · +9.5 vs tour on the same sequence
  4. FH crosscourt → FH through the middle → BH crosscourt used 0.8% · won 49% · +3.3±11.6 vs own baseline · −0.4 vs tour on the same sequence Disrupted by Cadence Brace (5/8)
  5. BH through the middle → FH crosscourt → FH through the middle used 0.6% · won 49% · +3.1±12.4 vs own baseline · +13.6 vs tour on the same sequence
  6. FH crosscourt → FH crosscourt → FH down the line used 1.2% · won 47% · +2.0±10.2 vs own baseline · +1.0 vs tour on the same sequence

Strengths and vulnerabilities

Value per 100 shots compared with the average player hitting (strengths) or facing (vulnerabilities) the same shot. Only shot types seen at least 120 times.

Hurts opponents most with

Wide 2nd serve · ad court+3.5133
FH to the middle · serve +1+1.1176
BH to the middle · rally+0.9283
FH to their backhand · rally+0.8309
BH to the middle · return+0.7362

Most exposed to

FH to their backhand · serve +1−2.6219
BH to their backhand · rally−1.3270
BH to the middle · return−1.3301
FH to the middle · rally−1.1227
Wide 1st serve · ad court−0.4268

Best-equipped opponents

Active players whose shot mix lines up best against these weaknesses, by structural compatibility per 100 rally shots: Sara Sorribes Tormo +2.65, Caroline Wozniacki +2.31, Daria Kasatkina +1.71, Sara Errani +1.58, Angelique Kerber +1.44

Favourable matchups

Sara Errani +1.36, Angelique Kerber +1.16, Marie Bouzkova +1.08, Elina Avanesyan +0.85, Linda Fruhvirtova +0.80

Active players who are best at the shot in the top weakness: Katie Boulter, Linda Fruhvirtova, Sara Errani, Leylah Fernandez, Karolina Muchova

Tactical fingerprint

Each bar shows how far a style trait is from the WTA average, in standard deviations.

T serves · deuce49%
Drop shots / shot3.2%
Wide serves · ad55%
Through the middle33%
Run-around forehands11%
Forehand share56%
Unforced errors / shot11.5%
Avg rally length4.3
Points at net8%
Chipped returns11%
Serve & volley1%
Point-ending shots24.0%
Deep returns33%
Backhand slice15%
FH down the line29%
BH down the line19%
1st serve in60%
T serves · ad26%
Wide serves · deuce30%

Plays most like

  1. Marta Kostyuk 2018–2026 plan v
  2. Leylah Fernandez 2020–2026 plan v
  3. Olga Danilovic 2019–2026 plan v
  4. Jil Teichmann 2017–2026 plan v
  5. Diana Shnaider 2022–2026 plan v
  6. Kiki Bertens 2012–2021 plan v
  7. Tiantsoa Sarah Rakotomanga Rajaonah 2025–2025 plan v
  8. Sara Bejlek 2022–2026 plan v

Closest from another era

  1. Monica Seles 1990–2003
  2. Elena Dementieva 1999–2010
  3. Jelena Dokic 2000–2009

Charted matches