Game plan

Lois Boisson v Maja Chwalinska

Every number combines what Lois Boisson does well with what Maja Chwalinska allows, each measured against the tour average and shrunk toward it when the sample is thin. Flip perspective

Forecast

Lois Boisson wins, best of 3 55%90%: 13%–91% · best of 5: 56%

Serve points won 58.2% / 57.3% Lois / Maja · tour 56.4%

Strengths only, no similarity priors 55%serve 58.2% / 57.3%

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 At least one of them is no longer active or has too little charted in the last three seasons, so both are compared on their careers.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 Lois Boisson's record against Maja Chwalinska'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.

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.

Lois Boisson serving

Deuce court

1st serve	Now	Lois wins	v Maja	Matchup	Optimal
Wide	37%	70%	58%	62.2%±10.9	52% ▲
Body	16%	65%	57%	64.2%±12.8	16%
T	47%	68%	62%	62.3%±12.2	32% ▼

Optimal v Maja Chwalinska: +0.3±1.2 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving body every time would read +1.7 per 100 first serves in before the returner adjusts.

Ad court

1st serve	Now	Lois wins	v Maja	Matchup	Optimal
Wide	49%	75%	59%	69.3%±11.2	63% ▲
Body	10%	60%	53%	56.4%±14.7	0% ▼
T	41%	66%	58%	59.3%±11.1	37% ▼

Optimal v Maja Chwalinska: +0.4±1.0 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +5.4 per 100 first serves in before the returner adjusts.

Maja Chwalinska serving

Deuce court

1st serve	Now	Maja wins	v Lois	Matchup	Optimal
Wide	26%	62%	64%	59.5%±12.1	26%
Body	28%	55%	63%	60.9%±13.0	13% ▼
T	46%	65%	75%	72.7%±10.5	61% ▲

Optimal v Lois Boisson: +0.2±1.2 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving T every time would read +6.8 per 100 first serves in before the returner adjusts.

Ad court

1st serve	Now	Maja wins	v Lois	Matchup	Optimal
Wide	53%	60%	70%	65.0%±10.7	52%
Body	22%	53%	54%	50.0%±14.3	7% ▼
T	26%	67%	67%	69.2%±11.8	41% ▲

Optimal v Lois Boisson: +0.8±1.3 per 100 first serves (faults included) over the current mix, inside the 90% margin. 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.

Lois Boisson returning

1st serve to the forehand

Return	Now	Tour	Own	v Maja	Value
FH through the middle	56%	+4.2	+1.8	+0.2	+6.2±3.1
FH crosscourt	18%	+5.3	−2.0	+2.7	+6.0±4.0
FH down the line	18%	+1.5	−1.2	+3.2	+3.5±4.3
FH slice through the middle	9%	−6.7	−0.1	−1.2	−8.0±1.7

Lean FH through the middle: +1.8±1.7 per 100 returns v the current mix (79 returns charted)

1st serve to the backhand

Return	Now	Tour	Own	v Maja	Value
BH through the middle	65%	+6.0	+0.4	+2.1	+8.5±2.7
BH down the line	20%	+2.2	+0.2	+2.7	+5.1±4.2
BH slice down the line	15%	−12.5	−1.9	±0.0	−14.4±1.9

Lean BH through the middle: +4.1±1.3 per 100 returns v the current mix (60 returns charted)

2nd serve to the backhand

Return	Now	Tour	Own	v Maja	Value
FH through the middle	40%	−2.7	+0.1	−1.2	−3.8±2.6
FH inside-out	22%	+1.4	+1.1	−1.4	+1.0±3.8
BH through the middle	16%	−2.6	+0.7	+1.4	−0.5±2.4
FH inside-in	12%	+0.7	−0.3	+0.4	+0.9±3.9
BH slice through the middle	10%	−11.7	+0.2	±0.0	−11.5±1.1

Lean FH through the middle: −1.4±1.9 per 100 returns v the current mix (58 returns charted, inside the 90% margin)

Maja Chwalinska returning

1st serve to the forehand

Return	Now	Tour	Own	v Lois	Value
FH through the middle	41%	+4.2	+3.2	−1.4	+5.9±3.2
FH crosscourt	21%	+5.3	+3.3	−4.9	+3.7±4.1
FH slice through the middle	17%	−6.7	+1.6	+0.2	−4.9±2.2
FH down the line	14%	+1.5	+1.1	−1.3	+1.3±4.2
FH slice crosscourt	7%	−6.6	+1.5	±0.0	−5.2±1.4

Lean FH through the middle: +3.8±2.2 per 100 returns v the current mix (111 returns charted)

1st serve to the backhand

Return	Now	Tour	Own	v Lois	Value
BH through the middle	43%	+6.0	+1.2	−1.6	+5.6±2.9
BH crosscourt	33%	+7.7	+2.4	−1.4	+8.8±3.5
BH down the line	16%	+2.2	+3.6	−0.3	+5.5±4.7
BH slice through the middle	3%	−6.2	−0.5	±0.0	−6.8±1.2
BH slice crosscourt	3%	−4.2	+0.1	±0.0	−4.1±1.3

Lean BH crosscourt: +3.2±2.8 per 100 returns v the current mix (236 returns charted)

2nd serve to the backhand

Return	Now	Tour	Own	v Lois	Value
BH through the middle	31%	−2.6	+1.6	+0.7	−0.4±2.8
BH crosscourt	29%	+1.5	±0.0	+0.2	+1.7±3.3
FH through the middle	18%	−2.7	−1.1	−0.8	−4.6±2.2
BH down the line	11%	−0.5	−1.3	−0.2	−2.0±4.7
FH inside-in	5%	+0.7	+0.5	±0.0	+1.3±3.0

Lean BH crosscourt: +2.3±2.6 per 100 returns v the current mix (110 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 on hard. Each player's hard record is shrunk toward their all-surface one, so a thin sample on it moves the numbers only a little.

Lois Boisson

Favour

Shot	Edge	Own	Theirs
BH to the middle · return	+4.1±3.8	+1.4	+2.7
FH to their backhand · return	+1.2±5.7	−1.2	+2.4
FH to their backhand · rally	−0.5±5.8	+0.4	−0.9
FH to the middle · return	−0.8±4.1	−0.3	−0.5
FH to their backhand · serve +1	−1.0±6.1	−0.2	−0.8
FH to the middle · rally	−1.2±3.8	+1.4	−2.5

Avoid

Shot	Edge	Own	Theirs
FH to their forehand · rally	−1.6±5.3	+3.2	−4.7
FH to the middle · rally	−1.2±3.8	+1.4	−2.5
FH to their backhand · serve +1	−1.0±6.1	−0.2	−0.8
FH to the middle · return	−0.8±4.1	−0.3	−0.5
FH to their backhand · rally	−0.5±5.8	+0.4	−0.9

Maja Chwalinska

Favour

Shot	Edge	Own	Theirs
BH to the middle · return	+2.8±3.4	+3.3	−0.5
FH to their backhand · rally	+2.7±5.7	−0.6	+3.3
FH to their forehand · rally	+2.7±5.1	+4.1	−1.4
BH to their backhand · return	+1.9±4.5	+2.8	−0.8
BH to their backhand · rally	+1.0±4.2	+3.6	−2.6
BH to their backhand · serve +1	+0.8±4.8	+1.2	−0.5

Avoid

Shot	Edge	Own	Theirs
FH to their backhand · serve +1	−1.7±6.1	−2.6	+0.9
FH to the middle · rally	−0.3±3.7	+2.7	−2.9
FH to their forehand · serve +1	−0.2±5.4	+1.6	−1.8
BH to their backhand · serve +1	+0.8±4.8	+1.2	−0.5
BH to their backhand · rally	+1.0±4.2	+3.6	−2.6

Against Maja Chwalinska-like opponents

Lois Boisson v	Matches	Serve pts won	Return pts won
All charted opponents	–	60.0%	42.5%

Similar by tactical fingerprint: Magdalena Frech, Sara Bejlek, Kaja Juvan, Tiantsoa Sarah Rakotomanga Rajaonah, Sara Errani, Angelique Kerber, Brenda Fruhvirtova, Martina Trevisan, Kateryna Baindl, Agnieszka Radwanska. When two players have rarely met, their records against these lookalikes fill the gap.