Game plan

Katie Volynets v Sloane Stephens

Every number combines what Katie Volynets does well with what Sloane Stephens allows, each measured against the tour average and shrunk toward it when the sample is thin. Flip perspective

Forecast

Katie Volynets wins, best of 3 33%90%: 11%–64% · best of 5: 29%

Serve points won 53.8% / 57.1% Katie / Sloane · tour 56.3%

Strengths only, no similarity priors 36%serve 54.1% / 56.7%

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 At least one of them is no longer active or has too little charted in the last three seasons, so both are compared on their careers.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 Katie Volynets's record against Sloane Stephens's tactical lookalikes and in their charted head-to-heads (lookalikes: −5.3 on serve, −14.2 on return vs expectation (108 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

Career	Katie	Sloane
Direction choice	−0.17 ±0.13 better than 23%	−0.12 ±0.11 better than 32%
Shot selection	±0.00 ±0.15 better than 45%	−0.16 ±0.14 better than 31%
Execution	+1.57 ±0.45 better than 97%	−0.13 ±0.58 better than 56%
Points left on the table	2.59 ±0.19 lower than 53%	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: Katie Volynets +0.57, Sloane Stephens +0.90. 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.

Katie Volynets serving

Deuce court

1st serve	Now	Katie wins	v Sloane	Matchup	Optimal
Wide	47%	64%	66%	64.4%±6.3	62% ▲
Body	29%	52%	58%	52.2%±7.8	13% ▼
T	24%	58%	71%	61.3%±7.9	25%

Optimal v Sloane Stephens: +1.3±1.0 per 100 first serves (faults included) over the current mix. Serving wide every time would read +4.2 per 100 first serves in before the returner adjusts.

Ad court

1st serve	Now	Katie wins	v Sloane	Matchup	Optimal
Wide	28%	68%	64%	66.5%±7.4	43% ▲
Body	22%	54%	59%	56.8%±9.1	7% ▼
T	50%	59%	67%	61.7%±6.7	50%

Optimal v Sloane Stephens: +0.4±1.1 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +4.5 per 100 first serves in before the returner adjusts.

Sloane Stephens serving

Deuce court

1st serve	Now	Sloane wins	v Katie	Matchup	Optimal
Wide	50%	66%	66%	65.9%±6.0	65% ▲
Body	30%	56%	57%	55.8%±8.2	15% ▼
T	20%	63%	63%	57.4%±8.7	20%

Optimal v Katie Volynets: +0.5±1.0 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +4.7 per 100 first serves in before the returner adjusts.

Ad court

1st serve	Now	Sloane wins	v Katie	Matchup	Optimal
Wide	32%	60%	62%	55.6%±7.3	30% ▼
Body	13%	53%	52%	48.1%±10.2	0% ▼
T	55%	61%	64%	61.1%±6.8	70% ▲

Optimal v Katie Volynets: +0.8±1.0 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving T every time would read +3.5 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.

Katie Volynets returning

1st serve to the forehand

Return	Now	Tour	Own	v Sloane	Value
FH through the middle	49%	+4.2	+1.6	+1.2	+7.0±2.3
FH crosscourt	32%	+5.3	+1.3	+0.8	+7.4±3.8
FH down the line	11%	+1.5	−2.2	+0.6	−0.1±4.3
FH slice through the middle	5%	−6.7	−0.3	−1.7	−8.7±2.4
FH slice crosscourt	2%	−6.6	±0.0	−1.3	−7.9±2.3

Lean FH crosscourt: +2.4±2.9 per 100 returns v the current mix (372 returns charted, inside the 90% margin)

1st serve to the backhand

Return	Now	Tour	Own	v Sloane	Value
BH through the middle	49%	+6.0	+1.5	−0.4	+7.1±2.3
BH crosscourt	25%	+7.7	+4.0	+2.2	+13.9±3.3
BH down the line	12%	+2.2	+1.4	−1.0	+2.6±4.5
BH slice through the middle	8%	−6.2	±0.0	−0.4	−6.6±2.4
BH slice crosscourt	3%	−4.2	+0.5	±0.0	−3.7±2.3

Lean BH crosscourt: +7.6±2.8 per 100 returns v the current mix (294 returns charted)

2nd serve to the forehand

Return	Now	Tour	Own	v Sloane	Value
FH through the middle	54%	−3.2	+2.6	−0.2	−0.8±3.1
FH crosscourt	35%	+0.5	+1.2	+1.6	+3.3±4.4
FH down the line	11%	−0.6	−2.5	−0.9	−3.9±4.6

Lean FH crosscourt: +3.0±3.3 per 100 returns v the current mix (83 returns charted, inside the 90% margin)

2nd serve to the backhand

Return	Now	Tour	Own	v Sloane	Value
BH through the middle	48%	−2.6	+1.4	−2.3	−3.5±2.6
BH crosscourt	32%	+1.5	+3.5	−0.5	+4.5±3.3
BH down the line	20%	−0.5	−0.3	−0.4	−1.2±5.1

Lean BH crosscourt: +5.0±2.8 per 100 returns v the current mix (125 returns charted)

Sloane Stephens returning

1st serve to the forehand

Return	Now	Tour	Own	v Katie	Value
FH through the middle	37%	+4.2	+2.0	+1.9	+8.1±2.4
FH slice through the middle	20%	−6.7	−0.4	−0.5	−7.6±2.5
FH crosscourt	14%	+5.3	−1.5	+3.9	+7.7±4.0
FH down the line	13%	+1.5	−0.6	+1.9	+2.8±4.5
FH slice crosscourt	12%	−6.6	+0.3	−0.2	−6.5±2.6

Lean FH through the middle: +6.5±1.8 per 100 returns v the current mix (466 returns charted)

1st serve to the backhand

Return	Now	Tour	Own	v Katie	Value
BH through the middle	43%	+6.0	−0.1	+1.6	+7.6±2.3
BH crosscourt	32%	+7.7	+0.3	+2.6	+10.6±3.3
BH down the line	10%	+2.2	−3.1	+1.3	+0.4±4.7
BH slice through the middle	8%	−6.2	−2.7	+0.7	−8.2±2.3
BH slice crosscourt	4%	−4.2	−1.3	−0.7	−6.2±2.6

Lean BH crosscourt: +5.3±2.5 per 100 returns v the current mix (509 returns charted)

2nd serve to the forehand

Return	Now	Tour	Own	v Katie	Value
FH through the middle	58%	−3.2	+0.2	+2.0	−1.0±3.1
FH crosscourt	26%	+0.5	−1.5	+0.2	−0.8±4.3
FH down the line	10%	−0.6	−0.5	+2.7	+1.6±4.5
FH slice through the middle	6%	−15.2	−0.8	±0.0	−16.0±1.1

Lean FH crosscourt: +0.7±3.7 per 100 returns v the current mix (88 returns charted, inside the 90% margin)

2nd serve to the backhand

Return	Now	Tour	Own	v Katie	Value
BH through the middle	45%	−2.6	−0.9	+0.5	−3.1±2.7
BH crosscourt	41%	+1.5	−1.0	+1.0	+1.5±3.5
BH down the line	6%	−0.5	−0.1	+2.3	+1.6±4.7
FH through the middle	5%	−2.7	±0.0	+2.0	−0.7±2.4
FH inside-out	3%	+1.4	+2.3	+2.7	+6.4±3.6

Lean BH down the line: +2.2±4.8 per 100 returns v the current mix (299 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.

Katie Volynets

Favour

Shot	Edge	Own	Theirs
BH to their backhand · return	+4.8±2.9	+3.9	+1.0
FH to the middle · return	+4.3±2.0	+2.2	+2.1
FH to their forehand · return	+4.2±3.5	+2.4	+1.8
FH to the middle · serve +1	+3.2±2.3	+1.9	+1.3
BH to the middle · rally	+2.1±1.5	+2.6	−0.5
BH to their backhand · return +1	+2.1±3.0	+2.5	−0.4

Avoid

Shot	Edge	Own	Theirs
BH to the middle · return +1	−2.4±2.2	+0.2	−2.6
FH to their backhand · return	−1.8±3.9	−2.3	+0.5
FH to their backhand · rally	−1.7±2.3	+1.1	−2.8
FH to their backhand · serve +1	−1.5±3.1	+1.4	−2.9
BH to their forehand · return +1	−0.5±4.7	+2.5	−3.0

Sloane Stephens

Favour

Shot	Edge	Own	Theirs
FH to their backhand · return	+3.8±3.9	+0.8	+3.0
BH to their forehand · return +1	+3.6±4.6	+2.3	+1.3
BH to their backhand · return	+3.2±2.8	+0.1	+3.0
FH to the middle · return	+3.1±1.9	+0.2	+2.9
BH to their backhand · return +1	+2.6±3.0	+0.4	+2.2
BH to the middle · return	+2.4±1.9	−0.5	+2.9

Avoid

Shot	Edge	Own	Theirs
BH slice to the middle · rally	−3.6±2.3	−2.6	−1.0
BH to the middle · return +1	−2.0±2.2	−2.8	+0.8
BH slice to their backhand · rally	−1.4±2.9	−0.5	−0.9
BH to their backhand · rally	±0.0±2.0	−0.5	+0.4
FH to the middle · rally	±0.0±1.6	−2.5	+2.4

Against Sloane Stephens-like opponents

Katie Volynets v	Matches	Serve pts won	Return pts won
All charted opponents	–	55.8%	44.0%
Players most similar to Sloane Stephens	1	48.4%	28.3%

Similar by tactical fingerprint: Coco Gauff, Iva Jovic, Eva Lys, Marie Bouzkova, Kimberly Birrell, Emma Raducanu, Paula Badosa, Lin Zhu, Carla Suarez Navarro, Marion Bartoli. When two players have rarely met, their records against these lookalikes fill the gap.