RallyIQ

Game plan

Juncheng Shang v John Isner

Every number combines what Juncheng Shang does well with what John Isner allows, each measured against the tour average and shrunk toward it when the sample is thin. Flip perspective

Forecast

Juncheng Shang wins, best of 3 41%90%: 24%–60% · best of 5: 39%
Serve points won 69.6% / 71.6% Juncheng / John · tour 63.8%
Strengths only, no similarity priors 41%serve 69.6% / 71.6%

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 At least one of them is no longer active or has too little charted in the last three seasons, so both are compared on their careers.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

CareerJunchengJohn
Direction choice−0.21 ±0.13
better than 13%
−0.13 ±0.05
better than 25%
Shot selection+0.51 ±0.30
better than 94%
+0.62 ±0.09
better than 96%
Execution−0.47 ±0.59
better than 46%
−0.90 ±0.33
better than 28%
Points left on the table3.00 ±0.24
lower than 19%
2.98 ±0.11
lower than 20%

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.

Juncheng Shang serving

Deuce court

1st serveNowJuncheng winsv JohnMatchupOptimal
Wide35%74%79%79.5%±6.248% ▲
Body13%60%76%73.2%±8.20% ▼
T52%67%84%78.4%±4.952%

Optimal v John Isner: +0.7±0.8 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving wide every time would read +1.4 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowJuncheng winsv JohnMatchupOptimal
Wide55%65%83%77.3%±5.055%
Body16%68%70%75.0%±8.13% ▼
T29%72%80%80.6%±6.642% ▲

Optimal v John Isner: +0.7±0.8 per 100 first serves (faults included) over the current mix, inside the 90% margin. Serving T every time would read +2.7 per 100 first serves in before the returner adjusts.

John Isner serving

Deuce court

1st serveNowJohn winsv JunchengMatchupOptimal
Wide52%78%70%76.2%±5.347% ▼
Body9%61%65%63.3%±11.40% ▼
T39%78%78%80.6%±5.253% ▲

Optimal v Juncheng Shang: +0.9±0.7 per 100 first serves (faults included) over the current mix. Serving T every time would read +3.8 per 100 first serves in before the returner adjusts.

Ad court

1st serveNowJohn winsv JunchengMatchupOptimal
Wide47%80%69%76.7%±5.840% ▼
Body6%66%63%65.7%±10.20% ▼
T47%79%73%80.1%±5.660% ▲

Optimal v Juncheng Shang: +0.6±0.6 per 100 first serves (faults included) over the current mix, inside the 90% margin. 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.

Juncheng Shang returning

1st serve to the forehand

ReturnNowTourOwnv JohnValue
FH through the middle53%+4.3+1.4−1.7+3.9±2.4
FH down the line20%+1.7−0.5−1.7−0.5±3.9
FH crosscourt16%+5.5+1.6−0.6+6.5±3.7
FH slice through the middle7%−4.2−1.0−1.6−6.8±1.8
FH slice crosscourt4%−4.3−0.5−1.7−6.5±2.3

Lean FH crosscourt: +4.3±3.5 per 100 returns v the current mix (166 returns charted)

1st serve to the backhand

ReturnNowTourOwnv JohnValue
BH through the middle46%+6.4+0.8−2.2+5.0±2.3
BH crosscourt26%+8.8+0.5+1.7+11.1±3.4
BH down the line14%+4.2−1.7−0.1+2.4±3.9
BH slice through the middle10%−4.2−1.3−2.2−7.6±2.0
BH slice down the line4%−8.4−0.2+0.4−8.2±2.6

Lean BH crosscourt: +6.7±2.8 per 100 returns v the current mix (175 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv JohnValue
FH through the middle60%−3.5+1.2−1.7−4.0±2.5
FH crosscourt32%−0.2−2.2−1.1−3.5±4.0
FH down the line8%−1.8−1.2−2.5−5.4±3.7

Lean FH crosscourt: +0.4±3.1 per 100 returns v the current mix (65 returns charted, inside the 90% margin)

2nd serve to the backhand

ReturnNowTourOwnv JohnValue
BH through the middle52%−2.9−0.7−3.1−6.7±2.1
BH crosscourt20%+1.0+2.3−3.8−0.5±3.0
BH down the line18%−0.2+1.3−1.3−0.2±4.0
FH inside-in5%+0.6−1.9−1.1−2.4±3.4
FH through the middle5%−2.9+0.4−1.7−4.2±1.6

Lean BH down the line: +3.7±3.5 per 100 returns v the current mix (132 returns charted)

John Isner returning

1st serve to the forehand

ReturnNowTourOwnv JunchengValue
FH through the middle47%+4.3−1.2+1.0+4.0±2.4
FH down the line31%+1.7−1.9+1.2+0.9±3.6
FH crosscourt11%+5.5+0.9−0.2+6.2±3.9
FH slice through the middle5%−4.2+2.2−1.2−3.3±2.2
FH slice down the line4%−4.3+0.6±0.0−3.6±2.3

Lean FH crosscourt: +3.6±3.8 per 100 returns v the current mix (1500 returns charted, inside the 90% margin)

1st serve to the backhand

ReturnNowTourOwnv JunchengValue
BH through the middle47%+6.4−3.2+3.5+6.7±2.1
BH crosscourt19%+8.8−2.4+4.4+10.8±3.1
BH down the line14%+4.2−1.8−0.2+2.1±4.1
BH slice through the middle9%−4.2−1.4+0.2−5.5±2.4
BH slice crosscourt7%+0.5−4.8+1.5−2.7±2.8

Lean BH crosscourt: +6.3±2.8 per 100 returns v the current mix (1608 returns charted)

2nd serve to the forehand

ReturnNowTourOwnv JunchengValue
FH through the middle46%−3.5−2.6−0.3−6.3±2.7
FH down the line42%−1.8−4.5−0.6−6.9±4.3
FH crosscourt10%−0.2−5.4−2.2−7.8±4.3
FH slice through the middle2%−12.7−0.4±0.0−13.0±1.2

Lean FH through the middle: +0.6±2.3 per 100 returns v the current mix (367 returns charted, inside the 90% margin)

2nd serve to the backhand

ReturnNowTourOwnv JunchengValue
BH through the middle46%−2.9−2.8+1.1−4.6±2.1
BH crosscourt26%+1.0−3.3+0.4−1.9±2.9
BH down the line14%−0.2±0.0+1.5+1.3±4.7
FH inside-out7%+1.0+1.9−0.6+2.3±3.7
FH through the middle6%−2.9−2.5−0.3−5.6±2.4

Lean FH inside-out: +5.0±3.7 per 100 returns v the current mix (996 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 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.

Juncheng Shang

Favour

ShotEdgeOwnTheirs
BH to their forehand · rally+14.8±4.5+5.1+9.8
BH to their forehand · serve +1+5.1±6.2−3.3+8.5
FH to their backhand · serve +1+4.1±3.6+1.6+2.5
BH to their forehand · return +1+3.9±6.5±0.0+3.9
FH to their backhand · rally+3.3±2.8+1.1+2.2
FH to their forehand · serve +1+3.0±4.2−0.8+3.8

Avoid

ShotEdgeOwnTheirs
FH to their backhand · return−5.1±5.1−4.2−0.9
BH to the middle · return−2.5±2.6+0.4−3.0
FH to the middle · serve +1−2.2±3.1−0.3−1.8
FH to their forehand · return−1.6±5.7−1.3−0.3
BH to their backhand · rally−1.5±2.9−3.0+1.5

John Isner

Favour

ShotEdgeOwnTheirs
BH to the middle · rally+0.5±2.4−2.3+2.8
BH to their backhand · return+0.4±3.7−2.1+2.5
BH to the middle · return+0.2±2.3−2.9+3.1
BH to their forehand · return−0.1±5.1−4.0+3.9
BH to the middle · return +1−0.3±3.1−1.0+0.7
FH to the middle · return−1.5±2.8−1.2−0.4

Avoid

ShotEdgeOwnTheirs
FH to their backhand · serve +1−7.8±3.9−2.2−5.7
FH to their forehand · rally−7.1±3.5−5.3−1.8
FH to their backhand · return +1−6.5±4.6−4.5−2.0
BH slice to their backhand · rally−5.9±3.0−6.2+0.4
FH to the middle · serve +1−5.6±3.5−3.6−2.0

Against John Isner-like opponents

Juncheng Shang vMatchesServe pts wonReturn pts won
All charted opponents–61.3%36.6%

Similar by tactical fingerprint: Arthur Rinderknech, Felix Auger Aliassime, Alexei Popyrin, Giovanni Mpetshi Perricard, Reilly Opelka, Nicolas Jarry, Milos Raonic, Jeremy Chardy, Sam Querrey, Lukas Rosol. When two players have rarely met, their records against these lookalikes fill the gap.