RallyIQ

WTA · Left-handed · 2 charted matches · 2022–2024

Kayla Cross

Shot expected value

The share of points Kayla Cross 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 · 60 shots

OptionUsedWin %Tour
BH crosscourt 45% 43.7%±11.9 47.6%
BH through the middle 28% 53.1%±13.5 43.3%
BH slice crosscourt 17% 43.6%±14.9 40.4%

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

position worth 43% to the average player · 34 shots

OptionUsedWin %Tour
FH down the line 47% 44.4%±13.6 44.9%
FH through the middle 32% 46.0%±14.7 41.3%

Return +1: drive to your backhand side

position worth 44% to the average player · 25 shots

OptionUsedWin %Tour
BH crosscourt 60% 50.2%±13.9 47.8%
BH through the middle 40% 42.0%±14.8 43.0%

Serve under pressure

Deuce court

1st serveUsageBreak ptWon when in
Wide 51% 60% ▲ 71% / 66%
Body 22% 20% 61% / 57%
T 28% 20% 67% / 68%

65 normal · 5 break-point 1st serves

Ad court

1st serveUsageBreak ptWon when in
Wide 50% 38% ▼ 70% / 66%
Body 30% 50% ▲ 50% / 56%
T 20% 13% 62% / 64%

56 normal · 8 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 won
Wide51% 60.7%±9.9 n=36
Body21% 65.0%±11.7 n=15
T27% 59.2%±11.5 n=19

Consistent with an optimal mix (p = 0.59).

Ad court

1st serveUsagePoints won
Wide48% 66.0%±10.0 n=31
Body33% 53.6%±11.5 n=21
T19% 62.6%±12.3 n=12

Consistent with an optimal mix (p = 0.11).

Return by serve direction

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

ServeCourtDirectionPointsWonvs tour
1stAd courtBody 15 43% −1.3±12.1
1stAd courtT 35 33% −2.2±9.6
1stAd courtWide 3 40% +6.0±14.1
1stDeuce courtBody 10 42% −0.7±12.8
1stDeuce courtT 10 27% −5.5±11.5
1stDeuce courtWide 30 34% −0.3±10.0
2ndAd courtBody 11 50% −5.0±12.8
2ndAd courtT 11 52% −2.6±12.8
2ndAd courtWide 1 55% +1.5±14.7
2ndDeuce courtBody 11 59% +4.9±12.6
2ndDeuce courtT 2 59% +2.7±14.3
2ndDeuce courtWide 21 51% −2.5±11.5

Charted matches