RallyIQ

WTA · Right-handed · 2 charted matches · 2017–2019

Lara Arruabarrena

Shot expected value

The share of points Lara Arruabarrena 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 · 71 shots

OptionUsedWin %Tour
BH slice crosscourt 27% 36.1%±12.7 40.4%
BH through the middle 21% 50.5%±13.9 43.3%
BH crosscourt 20% 51.5%±14.1 47.6%

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

position worth 43% to the average player · 45 shots

OptionUsedWin %Tour
FH down the line 49% 47.6%±12.7 44.9%
FH through the middle 24% 39.6%±14.4 41.3%

Serve under pressure

Deuce court

1st serveUsageBreak ptWon when in
Wide 23% 0% ▼ 64% / 66%
Body 28% 43% ▲ 54% / 57%
T 49% 57% ▲ 68% / 68%

82 normal · 7 break-point 1st serves

Ad court

1st serveUsageBreak ptWon when in
Wide 61% 69% ▲ 66% / 66%
Body 14% 8% 56% / 56%
T 26% 23% 64% / 64%

66 normal · 13 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
Wide21% 53.2%±11.7 n=19
Body29% 46.6%±11.0 n=26
T49% 60.0%±9.4 n=44

Consistent with an optimal mix (p = 0.10).

Ad court

1st serveUsagePoints won
Wide62% 61.5%±9.0 n=49
Body13% 60.4%±12.7 n=10
T25% 59.8%±11.4 n=20

Consistent with an optimal mix (p = 0.95).

Return by serve direction

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

ServeCourtDirectionPointsWonvs tour
1stAd courtBody 9 44% +0.1±13.1
1stAd courtT 17 31% −4.3±11.1
1stAd courtWide 34 30% −4.2±9.4
1stDeuce courtBody 14 43% +0.1±12.3
1stDeuce courtT 22 32% −0.1±10.6
1stDeuce courtWide 30 34% −0.3±10.0
2ndAd courtBody 9 63% +7.8±12.7
2ndAd courtT 2 55% −0.3±14.5
2ndAd courtWide 20 60% +6.6±11.4
2ndDeuce courtBody 16 57% +2.8±12.0
2ndDeuce courtT 7 54% −2.5±13.5
2ndDeuce courtWide 8 53% −0.8±13.3

Charted matches