RallyIQ

Game plan

Alycia Parks v Sara Errani

Every number combines what Alycia Parks does well with what Sara Errani allows, each measured against the tour average and shrunk toward it when the sample is thin. Flip perspective

Forecast

Alycia Parks wins, best of 3 52%90%: 22%–81% · best of 5: 52%
Serve points won 52.3% / 51.9% Alycia / Sara · tour 56.3%
Strengths only, no similarity priors 52%serve 52.3% / 51.9%

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 At least one of them is no longer active or has too little charted in the last three seasons, so both are compared on their careers.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 Alycia Parks's record against Sara Errani's tactical lookalikes and in their charted head-to-heads. 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

CareerAlyciaSara
Direction choice+0.10 ±0.08
better than 73%
−0.23 ±0.11
better than 14%
Shot selection+0.28 ±0.12
better than 76%
−0.34 ±0.17
better than 19%
Execution−3.50 ±0.79
better than 0%
+1.67 ±0.48
better than 97%
Points left on the table2.57 ±0.13
lower than 55%
2.62 ±0.13
lower than 48%

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: Alycia Parks −1.11, Sara Errani +0.75. 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.

Alycia Parks serving

Deuce court

1st serveNowAlycia winsv SaraMatchupOptimal
Wide52%69%60%63.5%±6.751%
Body15%54%66%62.4%±10.30% ▼
T34%67%64%63.0%±8.149% ▲

Optimal v Sara Errani: +0.2±1.1 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +0.3 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowAlycia winsv SaraMatchupOptimal
Wide40%71%58%63.7%±8.040%
Body16%56%54%53.7%±10.41% ▼
T44%65%69%69.1%±6.959% ▲

Optimal v Sara Errani: +0.8±1.1 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving T every time would read +4.6 per 100 first serves in before the returner adjusts.

Sara Errani serving

Deuce court

1st serveNowSara winsv AlyciaMatchupOptimal
Wide35%54%71%59.5%±7.450% ▲
Body45%50%61%53.5%±7.630% ▼
T20%53%65%50.1%±8.920%

Optimal v Alycia Parks: +0.5±1.0 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +4.6 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowSara winsv AlyciaMatchupOptimal
Wide37%54%66%54.2%±7.337%
Body46%53%61%58.3%±7.931% ▼
T17%53%68%57.7%±9.732% ▲

Optimal v Alycia Parks: +0.3±1.1 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving body every time would read +1.6 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.

Alycia Parks returning

1st serve to the forehand

ReturnNowTourOwnv SaraValue
FH through the middle40%+4.2−4.9+0.5−0.3±2.7
FH crosscourt23%+5.3+0.8+5.9+12.0±3.9
FH down the line21%+1.5−4.3+6.0+3.3±4.3
FH slice through the middle11%−6.7−2.3+0.1−8.9±2.1
FH slice down the line3%−10.5−1.2±0.0−11.7±1.7

Lean FH crosscourt: +10.1±3.3 per 100 returns v the current mix (337 returns charted)

1st serve to the backhand

ReturnNowTourOwnv SaraValue
BH through the middle50%+6.0−3.8+1.7+3.9±2.3
BH crosscourt25%+7.7−3.1+4.0+8.6±3.1
BH down the line18%+2.2+0.1+6.9+9.2±4.5
BH slice through the middle3%−6.2−1.4+0.7−6.9±1.8
BH slice crosscourt2%−4.2−0.6−0.4−5.2±2.2

Lean BH down the line: +4.0±3.9 per 100 returns v the current mix (344 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv SaraValue
FH through the middle40%−3.2−1.0−0.9−5.0±3.1
FH down the line35%−0.6−4.2+7.1+2.3±5.1
FH crosscourt20%+0.5+3.5+3.9+8.0±4.2
FH slice through the middle5%−15.2−0.7±0.0−15.9±1.1

Lean FH crosscourt: +8.4±4.0 per 100 returns v the current mix (96 returns charted)

2nd serve to the backhand

ReturnNowTourOwnv SaraValue
BH through the middle43%−2.6+1.7−0.5−1.4±2.7
BH crosscourt34%+1.5+1.1+0.3+2.9±3.7
BH down the line24%−0.5−0.8+3.4+2.1±5.2

Lean BH crosscourt: +2.1±3.0 per 100 returns v the current mix (148 returns charted, inside the 90% margin)

Sara Errani returning

1st serve to the forehand

ReturnNowTourOwnv AlyciaValue
FH through the middle42%+4.2+2.7+0.8+7.6±2.7
FH down the line23%+1.5+4.7+1.3+7.6±4.6
FH crosscourt16%+5.3+0.6−0.4+5.5±4.4
FH slice through the middle13%−6.7+0.5+1.4−4.9±2.6
FH slice down the line6%−10.5−0.1−0.7−11.2±3.2

Lean FH through the middle: +3.1±2.0 per 100 returns v the current mix (394 returns charted)

1st serve to the backhand

ReturnNowTourOwnv AlyciaValue
BH through the middle37%+6.0+1.9+0.2+8.1±2.7
BH crosscourt34%+7.7+1.5−1.7+7.5±3.6
BH slice through the middle13%−6.2+1.7−0.1−4.7±2.6
BH slice crosscourt7%−4.2−0.1+0.4−3.8±2.8
BH slice down the line5%−12.5+0.5−1.7−13.7±2.9

Lean BH through the middle: +4.0±2.1 per 100 returns v the current mix (315 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv AlyciaValue
FH through the middle45%−3.2+2.0+1.9+0.7±2.9
FH crosscourt30%+0.5+0.3+0.6+1.5±4.4
FH down the line26%−0.6+0.9−2.7−2.3±5.1

Lean FH crosscourt: +1.3±3.6 per 100 returns v the current mix (94 returns charted, inside the 90% margin)

2nd serve to the backhand

ReturnNowTourOwnv AlyciaValue
BH crosscourt55%+1.5+1.4−1.9+0.9±3.6
BH through the middle29%−2.6+0.5+0.4−1.7±2.7
FH inside-out8%+1.4+0.6−2.7−0.7±3.9
FH through the middle4%−2.7+0.3+1.9−0.5±2.0
BH down the line3%−0.5−0.6−2.9−4.0±4.2

Lean BH crosscourt: +1.1±1.8 per 100 returns v the current mix (146 returns charted, inside the 90% margin)

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.

Alycia Parks

Favour

ShotEdgeOwnTheirs
BH to their forehand · return+5.1±4.0−2.7+7.7
FH to their forehand · return+5.0±3.7−1.6+6.6
BH to their backhand · return+4.4±2.8−0.4+4.8
BH to their backhand · return +1+1.9±3.2−1.8+3.7
FH to their backhand · return+1.0±3.5−6.5+7.5
BH to the middle · return+0.9±2.0−2.5+3.4

Avoid

ShotEdgeOwnTheirs
BH to their backhand · rally−5.7±2.5−7.8+2.1
BH to the middle · rally−4.9±2.0−6.5+1.6
BH to their backhand · serve +1−4.2±3.1−4.7+0.5
FH to the middle · rally−4.1±2.3−4.9+0.8
BH to their forehand · serve +1−3.5±4.6−7.0+3.5

Sara Errani

Favour

ShotEdgeOwnTheirs
BH to their forehand · rally+4.9±4.3+3.7+1.3
FH to their backhand · serve +1+3.7±3.7+3.0+0.7
BH to their backhand · return +1+3.6±3.3+3.2+0.4
FH to the middle · rally+3.4±2.1+2.4+1.0
FH to the middle · return +1+2.6±2.7+1.7+0.9
BH to the middle · serve +1+2.6±2.2+1.9+0.7

Avoid

ShotEdgeOwnTheirs
FH to their forehand · rally−2.3±2.8+1.7−4.0
BH to their forehand · serve +1−1.8±4.9+0.4−2.3
FH to their forehand · serve +1−1.8±3.7+3.0−4.8
BH to their backhand · rally−1.0±2.7+0.4−1.4
FH to their backhand · rally−0.9±3.0+2.1−3.0

Against Sara Errani-like opponents

Alycia Parks vMatchesServe pts wonReturn pts won
All charted opponents–54.2%40.4%

Similar by tactical fingerprint: Tamara Zidansek, Viktorija Golubic, Daria Kasatkina, Maja Chwalinska, Sara Sorribes Tormo, Lesia Tsurenko, Alize Cornet, Kateryna Baindl, Madison Brengle, Tereza Martincova. When two players have rarely met, their records against these lookalikes fill the gap.