RallyIQ

WTA · Right-handed · 52 charted matches · 2001–2021

Kim Clijsters

Archetype: Forehand line-changer · Backhand line-changer

Against an average opponent

Serve points won 59.3% ±2.8 raw 58.2% · tour 56.3% · 3,675 points
Return points won 48.1% ±2.9 raw 46.5% · tour 43.7% · 3,732 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 +0.44 ±0.06 better than 98% of WTA · raw +0.44
Shot selection −0.25 ±0.09 better than 24% of WTA · raw −0.26
Execution +0.31 ±0.39 better than 73% of WTA · raw +0.20
Tactical adaptability +0.06 first serves toward what's working, set to set · 52 matches
Adaptation speed −0.17 same, every two to three service games · per 100 first serves
Points left on the table 2.06 per 100 shots vs best direction · lower than 98% 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 19,547 shots.

Shot expected value

The share of points Kim Clijsters 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 · 1,270 shots

OptionUsedWin %Tour
BH crosscourt 47% 51.6%±3.3 47.6%
BH through the middle 20% 48.9%±5.0 43.3%
BH down the line 17% 52.1%±5.4 46.8%
BH slice crosscourt 7% 41.5%±7.7 40.4%
BH slice through the middle 5% 31.9%±8.7 34.4%
FH inside-out 1% 70.5%±12.0 52.5%
BH slice down the line 1% 32.4%±13.0 31.7%

Rally, shots 5–8: drive to your middle

position worth 50% to the average player · 1,115 shots

OptionUsedWin %Tour
FH crosscourt 32% 54.7%±4.2 52.7%
FH down the line 19% 52.1%±5.4 52.2%
BH crosscourt 15% 54.6%±6.0 50.9%
BH through the middle 11% 47.1%±6.8 46.2%
FH through the middle 10% 53.3%±7.3 45.8%
BH down the line 9% 43.0%±7.4 50.0%
FH down the line + approach 1% 68.7%±12.7 68.6%
FH crosscourt + approach 1% 77.0%±11.7 69.7%

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

position worth 43% to the average player · 1,084 shots

OptionUsedWin %Tour
FH crosscourt 49% 49.8%±3.5 46.7%
FH down the line 21% 43.9%±5.1 44.9%
FH through the middle 18% 48.5%±5.6 41.3%
FH slice through the middle 5% 34.0%±8.8 29.2%
FH slice crosscourt 4% 50.6%±10.6 31.9%

Return +1: drive to your backhand side

position worth 44% to the average player · 668 shots

OptionUsedWin %Tour
BH crosscourt 61% 48.3%±4.0 47.8%
BH through the middle 19% 46.7%±6.8 43.0%
BH down the line 9% 49.7%±9.3 46.2%
BH slice crosscourt 6% 39.9%±10.4 39.6%
BH slice through the middle 4% 37.3%±11.2 33.2%

Serve under pressure

Pressure predictability index +2 How much less varied Kim Clijsters's first-serve direction gets on break points. Positive means easier to read. Based on 375 break-point first serves.

Deuce court

1st serveUsageBreak ptWon when in
Wide 58% 60% 67% / 66%
Body 9% 9% 60% / 57%
T 32% 31% 70% / 68%

1,790 normal · 95 break-point 1st serves

Ad court

1st serveUsageBreak ptWon when in
Wide 44% 40% 66% / 66%
Body 13% 11% 56% / 56%
T 43% 48% 61% / 64%

1,468 normal · 280 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
Wide58% 60.0%±2.4 n=1,099 53% ▼
Body10% 54.8%±5.7 n=179 0% ▼
T32% 61.1%±3.2 n=607 47% ▲

Consistent with an optimal mix (p = 0.18).
Optimal mix: +0.7 per 100 first serves.

Ad court

1st serveUsagePoints wonOptimal
Wide43% 57.6%±2.9 n=758 58% ▲
Body12% 55.5%±5.2 n=217 0% ▼
T44% 55.1%±2.9 n=773 42% ▼

Consistent with an optimal mix (p = 0.53).
Optimal mix: +0.5 per 100 first serves.

Exploitability 0.62 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: +0.3±2.7 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. (1,523 repeats, 2,006 switches.)

Return by serve direction

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

ServeCourtDirectionPointsWonvs tour
1stAd courtBody 175 48% +4.0±5.7
1stAd courtT 554 39% +3.5±3.3
1stAd courtWide 375 38% +3.9±4.0
1stDeuce courtBody 191 44% +1.6±5.5
1stDeuce courtT 429 36% +4.0±3.7
1stDeuce courtWide 514 36% +1.9±3.4
2ndAd courtBody 168 53% −2.3±5.8
2ndAd courtT 177 60% +5.1±5.6
2ndAd courtWide 342 59% +5.6±4.2
2ndDeuce courtBody 259 58% +3.8±4.8
2ndDeuce courtT 304 58% +1.7±4.4
2ndDeuce courtWide 211 57% +3.5±5.2

Signature patterns

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

Serve → +1

  1. T serve (deuce court) → FH crosscourt used 2.4% · won 60% · −3.1±7.7 vs own baseline
  2. Body serve (ad court) → BH crosscourt used 2.8% · won 60% · −3.4±7.3 vs own baseline
  3. T serve (deuce court) → BH crosscourt used 2.6% · won 60% · −3.5±7.6 vs own baseline
  4. Wide serve (ad court) → FH crosscourt used 2.8% · won 60% · −3.7±7.4 vs own baseline
  5. Wide serve (ad court) → BH down the line used 2.3% · won 58% · −5.1±8.0 vs own baseline

Return

  1. vs wide serve (ad court) → BH crosscourt, mid used 4.9% · won 59% · +11.3±6.0 vs own baseline
  2. vs T serve (deuce court) → BH through the middle, mid used 3.6% · won 60% · +12.2±6.8 vs own baseline
  3. vs T serve (ad court) → FH through the middle, deep used 2.2% · won 60% · +12.2±8.2 vs own baseline
  4. vs T serve (deuce court) → BH through the middle, deep used 3.7% · won 54% · +6.7±6.8 vs own baseline
  5. vs T serve (deuce court) → BH crosscourt, mid used 3.5% · won 54% · +6.8±7.0 vs own baseline

Rally, consecutive own shots

  1. FH crosscourt → FH crosscourt used 6.1% · won 60% · +7.8±4.8 vs own baseline
  2. FH down the line → FH crosscourt used 2.5% · won 62% · +10.5±7.0 vs own baseline
  3. BH through the middle → BH crosscourt used 3.6% · won 59% · +7.2±6.1 vs own baseline
  4. FH crosscourt → BH crosscourt used 5.3% · won 58% · +5.9±5.1 vs own baseline
  5. FH down the line → FH down the line used 1.3% · won 59% · +7.3±8.9 vs own baseline

Discovered sequences

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

  1. FH down the line → BH through the middle → FH crosscourt used 0.7% · won 63% · +11.5±8.3 vs own baseline · +10.2 vs tour on the same sequence Disrupted by Anastasia Myskina (4/7), Justine Henin (7/11)
  2. BH crosscourt → BH through the middle → FH crosscourt used 1.5% · won 58% · +6.3±6.1 vs own baseline · +4.9 vs tour on the same sequence Disrupted by Na Li (1/12), Lindsay Davenport (2/6)
  3. FH down the line → BH slice through the middle → FH crosscourt used 0.3% · won 66% · +14.4±10.7 vs own baseline · +14.0 vs tour on the same sequence Disrupted by Justine Henin (5/9)
  4. FH crosscourt → FH through the middle → FH crosscourt used 0.8% · won 59% · +7.7±7.8 vs own baseline · +6.1 vs tour on the same sequence Disrupted by Justine Henin (5/10), Elena Dementieva (6/7)
  5. FH crosscourt → FH down the line → BH crosscourt used 1.8% · won 56% · +5.0±5.6 vs own baseline · +7.3 vs tour on the same sequence Disrupted by Na Li (4/12), Caroline Wozniacki (4/10)
  6. BH down the line → FH through the middle → FH crosscourt used 0.4% · won 62% · +10.1±9.7 vs own baseline · +14.3 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

FH to the middle · return +1+2.0180
BH to their forehand · serve +1+1.9165
FH to the middle · return+1.8575
FH to the middle · rally+1.4482
FH to their backhand · rally+1.2903

Most exposed to

FH to the middle · return +1−2.3201
BH slice to the middle · rally−1.7228
FH to their backhand · serve +1−1.5494
BH slice to the middle · return−1.4122
T 2nd serve · deuce court−1.3304

Active players who are best at the shot in the top weakness: Sara Sorribes Tormo, Caroline Wozniacki, Angelique Kerber, Arantxa Rus, Daria Kasatkina

Tactical fingerprint

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

Wide serves · deuce58%
T serves · ad44%
1st serve in65%
Wide serves · ad43%
Avg rally length4.2
Point-ending shots24.8%
FH down the line30%
Chipped returns11%
Unforced errors / shot10.6%
Serve & volley0%
BH down the line20%
Points at net6%
Backhand slice12%
Forehand share52%
Run-around forehands4%
Drop shots / shot1.0%
T serves · deuce32%
Deep returns29%
Through the middle21%

Plays most like

  1. Anastasia Potapova 2017–2026 plan v
  2. Elena Dementieva 1999–2010 plan v
  3. Anna Kalinskaya 2019–2026 plan v
  4. Belinda Bencic 2014–2026 plan v
  5. Svetlana Kuznetsova 2004–2021 plan v
  6. Maria Sharapova 2003–2020 plan v
  7. Jelena Dokic 2000–2009 plan v
  8. Ana Ivanovic 2007–2016 plan v

Closest from another era

  1. Jennifer Capriati 1990–2002
  2. Chris Evert 1979–1989
  3. Arantxa Sanchez Vicario 1988–2001

Charted matches