RallyIQ

Game plan

Samantha Stosur v Madison Keys

Every number combines what Samantha Stosur does well with what Madison Keys allows, each measured against the tour average and shrunk toward it when the sample is thin. Flip perspective

Forecast

Samantha Stosur wins, best of 3 14%90%: 4%–36% · best of 5: 9%
Serve points won 56.3% / 64.7% Samantha / Madison · tour 55.0%
Strengths only, no similarity priors 18%serve 56.9% / 64.1%

Each player's serve and return strength is fitted against every opponent they were charted against, so a record built on weak opponents counts for less. At least one of them is no longer active or has too little charted in the last three seasons, so both are compared on their careers. The result is then nudged by Samantha Stosur's record against Madison Keys's tactical lookalikes and in their charted head-to-heads (lookalikes: −8.8 on serve, −10.2 on return vs expectation (219 points)). A game-by-game Markov chain turns point odds into match odds; the 90% range covers the uncertainty in the two strengths, not the nudges. Charted matches lean toward big events, so treat this as a scouting estimate, not a betting line.

Head to head, per 100 shots

CareerSamanthaMadison
Direction choice+0.02 ±0.07
better than 56%
+0.06 ±0.06
better than 67%
Shot selection−0.03 ±0.15
better than 43%
+0.34 ±0.10
better than 83%
Execution−0.51 ±0.60
better than 32%
−0.69 ±0.38
better than 28%
Points left on the table2.77 ±0.11
lower than 26%
2.58 ±0.09
lower than 54%

Each player's career against an average tour player in the same position, adjusted for opponent strength, with a 90% margin (shots clustered by match). Points left on the table is the gap to the best-value direction for the same stroke, so lower is better. Percentiles are within each player's own tour. A side is highlighted only when the gap is larger than the margin on the difference.

Serve plan

The share of points the server wins when a first serve lands in that direction (hover a rate for its 90% interval; ± is the 90% margin). "Matchup" combines the server's rate with how this returner handles that serve. "Optimal" is the mix that wins most against this returner once they start reading a habit, at the response measured across the tour, and only within the range servers' habits actually vary. The gain over the current mix is how exploitable that mix is.

Samantha Stosur serving

Deuce court

1st serveNowSamantha winsv MadisonMatchupOptimal
Wide38%68%70%71.9%±5.550% ▲
Body19%56%57%56.4%±7.34% ▼
T43%64%67%62.7%±5.546% ▲

Optimal v Madison Keys: +0.6±0.8 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +6.9 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowSamantha winsv MadisonMatchupOptimal
Wide38%64%64%63.2%±5.638%
Body15%59%56%59.0%±8.30% ▼
T46%73%65%73.8%±5.262% ▲

Optimal v Madison Keys: +1.1±1.0 per 100 first serves (faults included) over the current mix. Serving T every time would read +6.3 per 100 first serves in before the returner adjusts.

Madison Keys serving

Deuce court

1st serveNowMadison winsv SamanthaMatchupOptimal
Wide50%69%74%77.0%±4.765% ▲
Body14%54%58%55.0%±8.10% ▼
T37%78%68%78.9%±4.435% ▼

Optimal v Samantha Stosur: +1.6±0.9 per 100 first serves (faults included) over the current mix. Serving T every time would read +4.2 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowMadison winsv SamanthaMatchupOptimal
Wide41%65%65%64.1%±5.737% ▼
Body11%54%58%55.4%±8.70% ▼
T48%71%69%74.8%±5.063% ▲

Optimal v Samantha Stosur: +1.3±0.8 per 100 first serves (faults included) over the current mix. Serving T every time would read +6.4 per 100 first serves in before the returner adjusts.

Return plan

Value of each return, in points per 100 returns against an average return of the same serve (direction, court, surface): the tour's result with that return, the returner's own edge with it, and what this server gives up when it comes back to that side. Returns with no charted direction are left out, so values compare with each other rather than with zero. Depth isn't a choice here: missed returns have no depth. Serve quality isn't charted, so a block through the middle partly reflects the serve that forced it.

Samantha Stosur returning

1st serve to the forehand

ReturnNowTourOwnv MadisonValue
FH through the middle48%+4.2−0.1−0.4+3.6±2.3
FH down the line22%+1.5−1.2±0.0+0.3±4.2
FH crosscourt20%+5.3−3.6−1.5+0.2±3.8
FH slice through the middle6%−6.7+0.4+0.8−5.5±2.3
FH slice crosscourt3%−6.6−0.9+0.2−7.3±2.5

Lean FH through the middle: +2.3±1.7 per 100 returns v the current mix (355 returns charted)

1st serve to the backhand

ReturnNowTourOwnv MadisonValue
BH through the middle37%+6.0+0.4−0.5+5.9±2.1
BH crosscourt19%+7.7−1.2+1.1+7.6±3.1
BH slice through the middle15%−6.2−0.3−2.0−8.6±2.5
BH down the line14%+2.2+3.5−0.8+4.9±4.5
BH slice crosscourt9%−4.2−2.1−0.6−6.8±3.0

Lean BH crosscourt: +5.2±2.7 per 100 returns v the current mix (468 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv MadisonValue
FH through the middle34%−3.2+2.8+0.8+0.5±2.8
FH crosscourt32%+0.5−3.5−0.3−3.2±4.0
FH down the line29%−0.6−4.2−2.5−7.2±4.9
FH slice through the middle5%−15.2+0.6±0.0−14.6±1.1

Lean FH through the middle: +4.2±2.6 per 100 returns v the current mix (111 returns charted)

2nd serve to the backhand

ReturnNowTourOwnv MadisonValue
FH through the middle21%−2.7±0.0+0.8−1.8±2.4
BH through the middle20%−2.6−0.5−0.2−3.3±2.4
FH inside-in18%+0.7+0.1−0.3+0.6±4.3
FH inside-out14%+1.4+0.8−2.5−0.3±4.0
BH slice crosscourt9%−7.5−2.3±0.0−9.7±1.9
BH crosscourt9%+1.5+0.4−0.4+1.4±2.9

Lean BH crosscourt: +4.1±2.9 per 100 returns v the current mix (247 returns charted)

Madison Keys returning

1st serve to the forehand

ReturnNowTourOwnv SamanthaValue
FH through the middle44%+4.2−6.1−0.2−2.1±2.2
FH crosscourt28%+5.3−2.5+0.9+3.7±3.8
FH down the line11%+1.5−4.7−0.9−4.1±4.6
FH slice through the middle11%−6.7−1.1−1.1−8.9±2.5
FH slice crosscourt3%−6.6−0.4−0.2−7.2±2.4

Lean FH crosscourt: +5.5±3.0 per 100 returns v the current mix (845 returns charted)

1st serve to the backhand

ReturnNowTourOwnv SamanthaValue
BH through the middle52%+6.0−1.6+0.5+4.9±1.9
BH crosscourt20%+7.7+1.1+1.9+10.6±2.9
BH down the line17%+2.2−1.7−2.4−1.9±4.2
BH slice through the middle5%−6.2−1.8−0.4−8.4±2.6
BH slice down the line3%−12.5−2.0−0.6−15.0±3.3

Lean BH crosscourt: +7.2±2.6 per 100 returns v the current mix (1240 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv SamanthaValue
FH through the middle38%−3.2+2.5+1.0+0.4±3.0
FH crosscourt30%+0.5+1.4−0.4+1.5±4.5
FH down the line21%−0.6−4.4−3.7−8.7±5.3
FH slice through the middle6%−15.2+1.4±0.0−13.8±1.5
FH slice crosscourt4%−14.9+0.5±0.0−14.4±1.5

Lean FH crosscourt: +4.3±3.5 per 100 returns v the current mix (217 returns charted)

2nd serve to the backhand

ReturnNowTourOwnv SamanthaValue
BH through the middle40%−2.6−0.7+1.5−1.8±2.2
BH crosscourt29%+1.5+0.8+2.3+4.6±3.2
BH down the line21%−0.5+1.7+1.7+2.9±5.0
FH inside-out4%+1.4+2.7−3.7+0.3±4.2
FH through the middle4%−2.7+0.1+1.0−1.5±2.5

Lean BH crosscourt: +3.3±2.7 per 100 returns v the current mix (569 returns charted)

Rally plan

Edge, in points per 100 shots: the hitter's skill with the shot (own) plus how much the receiver usually gives up against it (theirs), both measured against the tour average on clay. Each player's clay record is shrunk toward their all-surface one, so a thin sample on it moves the numbers only a little.

Samantha Stosur

Favour

ShotEdgeOwnTheirs
BH slice to the middle · return +1+5.2±3.2+2.4+2.8
BH to the middle · rally+2.9±2.9+1.7+1.2
FH to their backhand · return +1+2.8±5.0+2.2+0.6
FH to the middle · return+2.1±3.1−0.6+2.7
BH to their backhand · return+1.8±3.9+1.7+0.2
FH to the middle · serve +1+1.7±3.2+0.4+1.3

Avoid

ShotEdgeOwnTheirs
BH slice to their backhand · rally−5.0±3.8−1.1−3.9
BH to their forehand · serve +1−4.7±6.3−1.8−3.0
BH slice to the middle · return−4.4±3.4−1.7−2.8
BH to their backhand · rally−3.4±4.1−2.1−1.3
BH to their forehand · return−3.0±5.9±0.0−3.0

Madison Keys

Favour

ShotEdgeOwnTheirs
BH to their forehand · return+3.9±5.4+3.8+0.2
BH to their forehand · serve +1+3.0±6.2−3.0+6.0
FH to their forehand · return+2.0±5.4+2.6−0.6
FH to the middle · return +1+1.3±3.4−0.2+1.5
BH to their backhand · return+0.8±3.7−0.3+1.1
BH slice to their backhand · rally+0.7±4.0+1.9−1.2

Avoid

ShotEdgeOwnTheirs
BH to the middle · rally−5.0±2.8−4.0−1.0
BH slice to the middle · rally−4.8±3.2−1.7−3.1
FH to their backhand · return−4.5±5.4−0.3−4.2
FH to their backhand · rally−4.4±4.0−3.6−0.8
BH to the middle · return +1−4.0±3.2−3.7−0.2

Against Madison Keys-like opponents

Samantha Stosur vMatchesServe pts wonReturn pts won
All charted opponents–55.9%38.6%
Players most similar to Madison Keys2 49.6%30.4%

Similar by tactical fingerprint: Naomi Osaka, Karolina Pliskova, Dayana Yastremska, Anastasia Pavlyuchenkova, Shelby Rogers, Kaia Kanepi, Julia Goerges, Maria Sharapova, Ana Ivanovic, Daniela Hantuchova. When two players have rarely met, their records against these lookalikes fill the gap.