RallyIQ

ATP · Right-handed · 3 charted matches · 2022–2025

Billy Harris

Shot expected value

The share of points Billy Harris 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.

Long rally, 9+: drive to your backhand side

position worth 46% to the average player · 30 shots

OptionUsedWin %Tour
BH crosscourt 63% 32.3%±12.3 48.0%
BH through the middle 37% 41.2%±14.5 43.8%

Serve under pressure

Deuce court

1st serveUsageBreak ptWon when in
Wide 56% 40% ▼ 67% / 73%
Body 12% 20% ▲ 58% / 63%
T 32% 40% ▲ 81% / 75%

85 normal · 5 break-point 1st serves

Ad court

1st serveUsageBreak ptWon when in
Wide 61% 21% ▼ 75% / 73%
Body 7% 21% ▲ 63% / 63%
T 31% 57% ▲ 67% / 72%

67 normal · 14 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. No measurable response (−0.05 ± 0.15 points per 100 serves for every 10 points of habitual usage), measured from ATP 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
Wide56% 57.2%±9.1 n=50
Body12% 55.8%±12.8 n=11
T32% 66.7%±10.1 n=29

Consistent with an optimal mix (p = 0.16).

Ad court

1st serveUsagePoints won
Wide54% 65.2%±9.1 n=44
Body10% 57.6%±13.2 n=8
T36% 56.4%±10.6 n=29

Consistent with an optimal mix (p = 0.09).

Return by serve direction

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

ServeCourtDirectionPointsWonvs tour
1stAd courtBody 1 36% −1.2±14.2
1stAd courtT 20 21% −7.2±9.4
1stAd courtWide 25 22% −5.1±9.2
1stDeuce courtBody 4 38% +1.6±13.7
1stDeuce courtT 24 21% −3.7±9.2
1stDeuce courtWide 27 20% −7.6±8.6
2ndAd courtBody 8 50% +0.1±13.3
2ndAd courtT 5 45% −4.2±13.8
2ndAd courtWide 16 45% −3.8±12.1
2ndDeuce courtBody 13 46% −3.2±12.5
2ndDeuce courtT 9 46% −3.8±13.1
2ndDeuce courtWide 9 42% −6.0±13.0

Charted matches