RallyIQ

Game plan

Kiki Bertens v Ashleigh Barty

Every number combines what Kiki Bertens does well with what Ashleigh Barty allows, each measured against the tour average and shrunk toward it when the sample is thin. Flip perspective

Forecast

Kiki Bertens wins, best of 3 25%90%: 9%–48% · best of 5: 20%
Serve points won 57.4% / 62.7% Kiki / Ashleigh · tour 56.3%
Strengths only, no similarity priors 25%serve 57.6% / 62.8%

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 At least one of them is no longer active or has too little charted in the last three seasons, so both are compared on their careers.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 Kiki Bertens's record against Ashleigh Barty's tactical lookalikes and in their charted head-to-heads (lookalikes: −2.5 on serve, +0.9 on return vs expectation (827 points); head-to-head: +1.8 on serve, −0.3 on return vs expectation (769 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

CareerKikiAshleigh
Direction choice+0.08 ±0.04
better than 70%
+0.27 ±0.07
better than 93%
Shot selection−0.41 ±0.09
better than 17%
−1.27 ±0.17
better than 2%
Execution−0.19 ±0.21
better than 50%
+0.79 ±0.31
better than 87%
Points left on the table2.67 ±0.06
lower than 38%
2.65 ±0.10
lower than 42%

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.

Kiki Bertens serving

Deuce court

1st serveNowKiki winsv AshleighMatchupOptimal
Wide49%71%67%71.9%±3.850%
Body9%62%57%60.8%±6.80% ▼
T42%70%62%64.5%±4.150% ▲

Optimal v Ashleigh Barty: +0.2±0.5 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +4.1 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowKiki winsv AshleighMatchupOptimal
Wide56%70%64%68.5%±3.971% ▲
Body5%50%50%44.0%±8.20% ▼
T39%68%59%63.0%±4.529% ▼

Optimal v Ashleigh Barty: +0.6±0.6 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +3.4 per 100 first serves in before the returner adjusts.

Ashleigh Barty serving

Deuce court

1st serveNowAshleigh winsv KikiMatchupOptimal
Wide41%73%66%72.7%±3.856% ▲
Body8%64%59%65.4%±7.30% ▼
T51%78%64%75.1%±3.744% ▼

Optimal v Kiki Bertens: +0.5±0.6 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving T every time would read +1.8 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowAshleigh winsv KikiMatchupOptimal
Wide44%73%63%70.8%±4.438% ▼
Body9%62%58%63.3%±7.70% ▼
T47%73%64%72.4%±4.062% ▲

Optimal v Kiki Bertens: +1.2±0.6 per 100 first serves (faults included) over the current mix. Serving T every time would read +1.5 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.

Kiki Bertens returning

1st serve to the forehand

ReturnNowTourOwnv AshleighValue
FH through the middle46%+4.2+1.8−0.3+5.7±1.8
FH crosscourt16%+5.3+0.4−1.6+4.1±3.4
FH slice through the middle15%−6.7−4.0−1.6−12.3±2.1
FH down the line12%+1.5−1.2−2.9−2.5±3.8
FH slice crosscourt10%−6.6+1.5−0.4−5.5±2.6

Lean FH through the middle: +5.3±1.3 per 100 returns v the current mix (1802 returns charted)

1st serve to the backhand

ReturnNowTourOwnv AshleighValue
BH through the middle43%+6.0±0.0+1.8+7.8±1.8
BH crosscourt18%+7.7+0.2+0.2+8.1±2.8
BH slice through the middle15%−6.2−0.2−0.4−6.9±2.1
BH down the line14%+2.2−2.0−2.8−2.6±3.9
BH slice crosscourt5%−4.2−0.9+0.5−4.6±3.0

Lean BH crosscourt: +5.6±2.5 per 100 returns v the current mix (2080 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv AshleighValue
FH through the middle45%−3.2+1.1−0.1−2.2±2.6
FH crosscourt35%+0.5−1.1−1.3−1.8±4.0
FH down the line15%−0.6−0.8−1.7−3.1±5.1
FH slice through the middle3%−15.2+0.2+0.4−14.6±2.3
FH slice crosscourt1%−14.9+0.9±0.0−14.0±1.3

Lean FH crosscourt: +0.9±2.9 per 100 returns v the current mix (483 returns charted, inside the 90% margin)

2nd serve to the backhand

ReturnNowTourOwnv AshleighValue
BH through the middle40%−2.6−0.4+1.2−1.8±1.7
BH crosscourt32%+1.5−0.4−1.9−0.8±2.4
FH through the middle9%−2.7−0.4−0.1−3.2±2.4
FH inside-in8%+0.7+1.3−1.3+0.7±4.5
BH down the line7%−0.5−2.9+2.3−1.1±4.9

Lean FH inside-in: +2.0±4.3 per 100 returns v the current mix (1083 returns charted, inside the 90% margin)

Ashleigh Barty returning

1st serve to the forehand

ReturnNowTourOwnv KikiValue
FH through the middle43%+4.2±0.0−1.0+3.1±1.8
FH crosscourt25%+5.3−1.0+0.5+4.8±3.3
FH down the line17%+1.5+3.2−3.8+0.9±3.8
FH slice through the middle9%−6.7−0.6−0.7−8.0±2.2
FH slice crosscourt4%−6.6−1.0−0.3−7.9±2.7

Lean FH crosscourt: +3.4±2.7 per 100 returns v the current mix (769 returns charted)

1st serve to the backhand

ReturnNowTourOwnv KikiValue
BH slice through the middle29%−6.2+1.7−0.4−4.9±1.8
BH through the middle29%+6.0−0.9−0.8+4.3±1.8
BH crosscourt17%+7.7−0.3−2.2+5.2±2.7
BH slice crosscourt12%−4.2+0.7−3.0−6.4±2.8
BH down the line7%+2.2−0.2−4.8−2.8±4.1

Lean BH crosscourt: +5.9±2.4 per 100 returns v the current mix (911 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv KikiValue
FH crosscourt47%+0.5+2.4−4.5−1.6±3.9
FH through the middle40%−3.2−1.6+0.1−4.7±2.5
FH down the line13%−0.6+2.4−2.3−0.5±4.3

Lean FH down the line: +2.2±4.3 per 100 returns v the current mix (161 returns charted, inside the 90% margin)

2nd serve to the backhand

ReturnNowTourOwnv KikiValue
BH slice crosscourt24%−7.5−1.7−1.0−10.2±2.7
BH through the middle23%−2.6−3.0−0.9−6.5±2.0
BH crosscourt16%+1.5+1.4−2.1+0.8±2.9
BH slice through the middle14%−11.7−0.3+0.5−11.4±2.3
BH down the line7%−0.5−1.2−2.9−4.6±4.5

Lean BH crosscourt: +7.2±2.6 per 100 returns v the current mix (526 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.

Kiki Bertens

Favour

ShotEdgeOwnTheirs
BH to the middle · serve +1+1.8±1.8+1.3+0.5
FH to the middle · return+1.0±1.5+1.1−0.1
BH to the middle · return+0.5±1.2+0.6−0.1
FH to the middle · serve +1+0.4±1.8+1.0−0.6
FH slice to their backhand · rally+0.2±3.5+1.7−1.5
BH slice to the middle · return+0.2±2.1+0.5−0.3

Avoid

ShotEdgeOwnTheirs
BH to their forehand · serve +1−6.6±3.7−4.8−1.8
FH to their backhand · rally−6.0±1.5−1.3−4.7
BH volley to their forehand · rally−5.4±5.9+1.9−7.3
FH slice to the middle · return−4.7±2.1−3.0−1.7
FH to their backhand · return−4.6±2.9−1.8−2.7

Ashleigh Barty

Favour

ShotEdgeOwnTheirs
FH volley to their backhand · rally+2.3±5.6+2.3±0.0
BH to their backhand · return +1+1.1±2.6+0.6+0.5
BH slice to the middle · serve +1+1.1±2.4+1.6−0.4
FH to the middle · serve +1+1.1±1.6+0.9+0.2
FH to their backhand · return +1+0.6±2.8+1.4−0.8
BH slice to their forehand · return+0.4±3.3+0.8−0.5

Avoid

ShotEdgeOwnTheirs
BH slice to their backhand · return−5.4±2.4−2.5−3.0
BH to their forehand · return−5.2±3.4−0.9−4.3
FH volley to their forehand · rally−5.2±5.1+1.0−6.2
FH slice to their backhand · rally−3.9±3.5−2.8−1.0
BH to their forehand · serve +1−3.8±4.0−2.5−1.3

Against Ashleigh Barty-like opponents

Kiki Bertens vMatchesServe pts wonReturn pts won
All charted opponents–59.9%43.7%
Players most similar to Ashleigh Barty6 56.0%43.9%
Ashleigh Barty (charted head-to-head)4 59.3%36.9%

Similar by tactical fingerprint: Karolina Muchova, Barbora Krejcikova, Clara Tauson, Diane Parry, Maria Sakkari, Jennifer Brady, Polona Hercog, Francesca Schiavone, Roberta Vinci. When two players have rarely met, their records against these lookalikes fill the gap.

Charted head-to-head