RallyIQ

Game plan

Serena Williams v Madison Keys

Every number combines what Serena Williams 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

Serena Williams wins, best of 3 84%90%: 65%–95% · best of 5: 90%
Serve points won 66.1% / 58.2% Serena / Madison · tour 58.1%
Strengths only, no similarity priors 80%serve 65.5% / 58.8%

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 At least one of them is no longer active or has too little charted in the last three seasons, so both are compared on their careers.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 Serena Williams's record against Madison Keys's tactical lookalikes and in their charted head-to-heads (lookalikes: +0.3 on serve, +1.1 on return vs expectation (3209 points); head-to-head: +14.1 on serve, +0.8 on return vs expectation (110 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

CareerSerenaMadison
Direction choice+0.34 ±0.04
better than 97%
+0.06 ±0.06
better than 67%
Shot selection+0.47 ±0.05
better than 93%
+0.34 ±0.10
better than 83%
Execution−0.04 ±0.27
better than 59%
−0.69 ±0.38
better than 28%
Points left on the table2.20 ±0.07
lower than 94%
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.

Structural compatibility

Expected edge per 100 rally shots from style alone: Serena Williams −1.46, Madison Keys −1.71. Each player's shot mix weighted by their own skill with each shot and by how much the other gives up against it. This is why some rankings gaps don't hold in a given matchup.

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.

Serena Williams serving

Deuce court

1st serveNowSerena winsv MadisonMatchupOptimal
Wide50%70%70%73.7%±3.556% ▲
Body8%62%57%62.1%±5.70% ▼
T42%79%67%78.5%±3.044% ▲

Optimal v Madison Keys: +0.5±0.4 per 100 first serves (faults included) over the current mix. Serving T every time would read +3.7 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowSerena winsv MadisonMatchupOptimal
Wide45%75%64%74.0%±3.339% ▼
Body6%60%56%59.9%±6.80% ▼
T49%70%65%70.6%±3.861% ▲

Optimal v Madison Keys: +0.4±0.5 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +2.6 per 100 first serves in before the returner adjusts.

Madison Keys serving

Deuce court

1st serveNowMadison winsv SerenaMatchupOptimal
Wide50%69%65%68.0%±3.448% ▼
Body14%54%53%49.9%±6.00% ▼
T37%78%66%76.7%±3.652% ▲

Optimal v Serena Williams: +1.6±0.7 per 100 first serves (faults included) over the current mix. Serving T every time would read +7.9 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowMadison winsv SerenaMatchupOptimal
Wide41%65%66%65.4%±3.943% ▲
Body11%54%57%54.7%±6.80% ▼
T48%71%61%67.8%±3.657% ▲

Optimal v Serena Williams: +0.5±0.5 per 100 first serves (faults included) over the current mix. Serving T every time would read +2.4 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.

Serena Williams returning

1st serve to the forehand

ReturnNowTourOwnv MadisonValue
FH through the middle49%+4.2−2.6−0.4+1.1±1.6
FH crosscourt36%+5.3−1.6−1.5+2.2±2.7
FH down the line11%+1.5−0.4±0.0+1.1±3.7
BH through the middle1%+5.2−3.4−0.5+1.3±2.3
FH slice through the middle1%−6.7−0.7+0.8−6.6±2.1

Lean FH crosscourt: +0.7±2.0 per 100 returns v the current mix (2166 returns charted, inside the 90% margin)

1st serve to the backhand

ReturnNowTourOwnv MadisonValue
BH through the middle48%+6.0+0.3−0.5+5.8±1.5
BH crosscourt33%+7.7+1.3+1.1+10.2±2.2
BH down the line12%+2.2+1.1−0.8+2.5±3.9
BH slice through the middle3%−6.2−4.5−2.0−12.7±2.5
BH slice crosscourt2%−4.2−2.8−0.6−7.5±3.0

Lean BH crosscourt: +4.3±1.7 per 100 returns v the current mix (1939 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv MadisonValue
FH crosscourt43%+0.5−0.5−0.3−0.2±3.4
FH through the middle37%−3.2−0.1+0.8−2.4±2.3
FH down the line18%−0.6+5.3−2.5+2.2±4.6
BH inside-in1%+2.0−1.4−0.4+0.1±2.8
BH through the middle1%−1.0−0.2−0.2−1.4±1.8

Lean FH down the line: +2.8±4.2 per 100 returns v the current mix (750 returns charted, inside the 90% margin)

2nd serve to the backhand

ReturnNowTourOwnv MadisonValue
BH crosscourt51%+1.5+0.9−0.4+1.9±2.3
BH through the middle30%−2.6−1.8−0.2−4.6±1.9
BH down the line17%−0.5+3.4−2.9±0.0±4.6
FH inside-in1%+0.7+0.7−0.3+1.2±3.6
FH inside-out1%+1.4+0.2−2.5−1.0±3.3

Lean BH crosscourt: +2.4±1.5 per 100 returns v the current mix (954 returns charted)

Madison Keys returning

1st serve to the forehand

ReturnNowTourOwnv SerenaValue
FH through the middle44%+4.2−6.1−1.3−3.2±1.7
FH crosscourt28%+5.3−2.5−4.0−1.1±2.9
FH down the line11%+1.5−4.7−1.4−4.7±3.8
FH slice through the middle11%−6.7−1.1+2.1−5.7±2.2
FH slice crosscourt3%−6.6−0.4−2.4−9.4±2.7

Lean FH crosscourt: +2.3±2.3 per 100 returns v the current mix (845 returns charted, inside the 90% margin)

1st serve to the backhand

ReturnNowTourOwnv SerenaValue
BH through the middle52%+6.0−1.6−1.0+3.4±1.5
BH crosscourt20%+7.7+1.1−0.2+8.5±2.6
BH down the line17%+2.2−1.7−4.1−3.6±3.6
BH slice through the middle5%−6.2−1.8−0.2−8.2±2.3
BH slice down the line3%−12.5−2.0−1.2−15.6±3.6

Lean BH crosscourt: +6.6±2.3 per 100 returns v the current mix (1240 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv SerenaValue
FH through the middle38%−3.2+2.5−0.9−1.5±2.5
FH crosscourt30%+0.5+1.4−3.0−1.1±3.8
FH down the line21%−0.6−4.4+0.6−4.4±4.6
FH slice through the middle6%−15.2+1.4−0.4−14.2±2.1
FH slice crosscourt4%−14.9+0.5±0.0−14.4±2.2

Lean FH crosscourt: +2.3±3.0 per 100 returns v the current mix (217 returns charted, inside the 90% margin)

2nd serve to the backhand

ReturnNowTourOwnv SerenaValue
BH through the middle40%−2.6−0.7−0.3−3.6±1.8
BH crosscourt29%+1.5+0.8−0.2+2.1±2.6
BH down the line21%−0.5+1.7−2.1−0.9±4.2
FH inside-out4%+1.4+2.7+0.6+4.6±3.6
FH through the middle4%−2.7+0.1−0.9−3.5±2.0

Lean FH inside-out: +5.5±3.7 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 grass. Each player's grass record is shrunk toward their all-surface one, so a thin sample on it moves the numbers only a little.

Serena Williams

Favour

ShotEdgeOwnTheirs
FH to their forehand · return+5.4±4.7+1.9+3.5
FH to their backhand · rally+3.2±4.2+1.6+1.6
FH to their backhand · return+2.2±5.2+2.0+0.2
BH to their backhand · return+1.2±3.7+2.6−1.4
FH to the middle · serve +1+1.1±3.3−0.2+1.3
FH slice to the middle · rally+0.5±3.6−1.5+2.0

Avoid

ShotEdgeOwnTheirs
BH slice to the middle · return−10.0±3.1−8.4−1.6
FH to their forehand · rally−6.6±3.7−2.9−3.7
BH slice to their forehand · rally−6.6±4.4−5.6−1.0
BH slice to the middle · rally−6.2±3.2−4.8−1.4
BH slice to their backhand · rally−4.7±3.4−1.9−2.8

Madison Keys

Favour

ShotEdgeOwnTheirs
FH to their forehand · return +1+4.6±4.8+2.1+2.5
BH to their backhand · return +1+4.6±4.5+3.5+1.1
FH volley to their forehand · rally+2.9±7.5+1.2+1.7
FH to their forehand · serve +1+2.2±4.5−0.3+2.5
BH slice to their backhand · rally+1.9±3.8+1.1+0.8
FH slice to the middle · rally+0.7±3.6+1.8−1.1

Avoid

ShotEdgeOwnTheirs
BH to their forehand · serve +1−6.6±5.6−6.8+0.2
FH to the middle · return−5.2±3.0−3.1−2.1
BH to their forehand · return−5.0±5.0−1.2−3.8
BH to the middle · rally−3.9±2.7−4.7+0.8
BH to the middle · return +1−3.8±3.3−2.5−1.3

Against Madison Keys-like opponents

Serena Williams vMatchesServe pts wonReturn pts won
All charted opponents–62.1%45.1%
Players most similar to Madison Keys25 62.1%43.9%
Madison Keys (charted head-to-head)1 76.6%42.9%

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.

Charted head-to-head