RallyIQ

WTA · Right-handed · 5 charted matches · 1988–1991

Zina Garrison

Against an average opponent

Serve points won 53.3% ±4.1 raw 47.6% · tour 56.3% · 349 points
Return points won 45.6% ±4.1 raw 42.8% · tour 43.7% · 374 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.

Shot expected value

The share of points Zina Garrison 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 forehand side

position worth 43% to the average player · 52 shots

OptionUsedWin %Tour
FH crosscourt 48% 49.7%±12.3 46.7%
FH through the middle 23% 38.3%±14.1 41.3%

Return +1: drive to your forehand side

position worth 43% to the average player · 40 shots

OptionUsedWin %Tour
FH crosscourt 38% 47.2%±13.9 47.6%
FH down the line 38% 36.6%±13.4 44.1%
FH through the middle 25% 44.2%±14.9 41.3%

Serve under pressure

Pressure predictability index +4 How much less varied Zina Garrison's first-serve direction gets on break points. Positive means easier to read. Based on 52 break-point first serves.

Deuce court

1st serveUsageBreak ptWon when in
Wide 25% 17% ▼ 59% / 66%
Body 29% 42% ▲ 40% / 57%
T 46% 42% 59% / 68%

166 normal · 12 break-point 1st serves

Ad court

1st serveUsageBreak ptWon when in
Wide 55% 60% 66% / 66%
Body 31% 28% 51% / 56%
T 13% 13% 62% / 64%

127 normal · 40 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
Wide25% 42.4%±9.4 n=44
Body30% 39.7%±8.8 n=53
T46% 47.9%±7.8 n=81

Consistent with an optimal mix (p = 0.31).

Ad court

1st serveUsagePoints won
Wide56% 53.4%±7.4 n=94
Body31% 47.1%±9.1 n=51
T13% 50.8%±11.4 n=22

Consistent with an optimal mix (p = 0.48).

Repeating the previous direction to the same court: −6.1±8.1 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. (170 repeats, 165 switches.)

Return by serve direction

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

ServeCourtDirectionPointsWonvs tour
1stAd courtBody 19 47% +3.4±11.7
1stAd courtT 21 35% −0.9±11.0
1stAd courtWide 72 31% −3.7±7.5
1stDeuce courtBody 43 45% +2.3±9.6
1stDeuce courtT 38 29% −3.3±9.0
1stDeuce courtWide 44 38% +4.1±9.3
2ndAd courtBody 20 59% +4.0±11.4
2ndAd courtT 6 57% +1.9±13.6
2ndAd courtWide 40 50% −3.4±9.8
2ndDeuce courtBody 26 51% −3.9±11.0
2ndDeuce courtT 10 55% −1.5±13.0
2ndDeuce courtWide 21 57% +3.3±11.4

Signature patterns

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

Serve → +1

  1. Not enough data

Return

  1. vs wide serve (ad court) → BH slice crosscourt, mid used 33.0% · won 35% · −0.9±9.7 vs own baseline

Rally, consecutive own shots

  1. BH slice crosscourt → FH crosscourt used 27.0% · won 44% · +3.9±10.5 vs own baseline

Discovered sequences

Mined from every me → opponent → me run of three shots, with no templates. Ranked by how much more often Zina Garrison 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 slice crosscourt → BH slice crosscourt used 3.3% · won 40% · −4.2±12.9 vs own baseline · −9.1 vs tour on the same sequence Disrupted by Steffi Graf (5/15)

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

BH slice to their backhand · return+5.6123

Most exposed to

Charted matches