In Brouwers et al., 43.6% of 202 male ITF junior year-end top-20 players from 1988–1999 reached the ATP top 100 by 2008; 45.7% of 175 female junior year-end top-20 players from 1988–1998 reached the WTA top 100 by 2007. Source: doi:10.1016/j.smr.2012.05.002.
- Forward conversion
- The share of a defined junior cohort that later reached a stated professional ranking band.
- Reverse conversion
- The share of a defined professional cohort that had previously occupied a stated junior ranking band.
- Denominator
- The number of players in the cohort from which each percentage was calculated.
- Observation endpoint
- The final year through which the source checked later professional rankings.
What do junior-to-pro conversion rates mean?
A conversion rate describes the share of a defined historical group that later entered a defined professional ranking band. It is only interpretable when the junior band, professional target, denominator, cohort window and observation endpoint are reported together.
This review extracts the published “bottom-up” and “top-down” rates from Brouwers, De Bosscher and Sotiriadou’s study. The open institutional manuscript makes the complete tables inspectable. We did not reconstruct player histories or conduct a new cohort analysis.
Two directions answer different questions. Forward analysis asks what junior top-20 players later achieved. Reverse analysis asks how many professional top-20 players had previously occupied a junior ranking band. A reverse rate is not the probability that a junior will reach that professional band.
How many junior top-20 players reached the professional rankings?
| Junior population | Later target | Rate | Denominator | Cohort / endpoint |
|---|---|---|---|---|
| Male junior year-end top 20 | ATP top 200 | 65.8% | 202 | 1988–1999 / 2008 |
| Male junior year-end top 20 | ATP top 100 | 43.6% | 202 | 1988–1999 / 2008 |
| Male junior year-end top 20 | ATP top 20 | 16.8% | 202 | 1988–1999 / 2008 |
| Female junior year-end top 20 | WTA top 200 | 64.6% | 175 | 1988–1998 / 2007 |
| Female junior year-end top 20 | WTA top 100 | 45.7% | 175 | 1988–1998 / 2007 |
| Female junior year-end top 20 | WTA top 20 | 11.4% | 175 | 1988–1998 / 2007 |
How many professional top-20 players had strong junior rankings?
| Professional population | Prior junior band reached | Rate | Denominator | Window |
|---|---|---|---|---|
| ATP year-end top 20 | ITF junior top 200 | 76.5% | 68 | 2000–2008 |
| ATP year-end top 20 | ITF junior top 100 | 66.2% | 68 | 2000–2008 |
| ATP year-end top 20 | ITF junior top 20 | 44.1% | 68 | 2000–2008 |
| WTA year-end top 20 | ITF junior top 200 | 81.6% | 60 | 1999–2007 |
| WTA year-end top 20 | ITF junior top 100 | 75.0% | 60 | 1999–2007 |
| WTA year-end top 20 | ITF junior top 20 | 40.0% | 60 | 1999–2007 |
The reverse results show that strong junior performance was common among later top-20 professionals, but not universal. They do not contradict the lower forward conversion rates: the numerator, denominator and question have changed.
What should players and parents take from the evidence?
Top 100 was not automatic
In both forward cohorts, fewer than half of junior top-20 players later reached the professional top 100.
Alternative timelines existed
Some eventual professional top-20 players had never reached the junior top 200, so one junior ranking cut-off did not capture every path.
Junior ranking is useful evidence of competitive level, not a complete development diagnosis. Decisions should also examine health, rate of technical change, decision-making under pressure, training environment, education, finance and whether the player is still improving relative to age and opportunity.
Method, definitions and limitations
Extraction method
We transcribed the twelve percentages, denominators and cohort windows reported in the source study’s forward and reverse tables, then checked the web table, CSV and JSON against one another. No player-level records were added, removed or reclassified by Stakhovsky Tennis.
Definitions
- Junior top 20: an ITF junior year-end ranking band used by the source study.
- Professional top 200, 100 or 20: reaching the corresponding ATP or WTA ranking band within the source observation period.
- Forward: junior cohort to later professional outcome.
- Reverse: professional cohort to earlier junior ranking history.
Limitations
- The cohorts largely predate today’s pathway, ranking systems, competition calendar and economics.
- Rates for elite year-end junior top-20 groups must not be generalized to all ranked juniors.
- The source reports historical group associations, not causal effects or calibrated individual probabilities.
- Different observation endpoints mean male and female values should not be treated as a controlled sex comparison.
- Separate longitudinal studies of boys and girls use different samples and methods; their results should not be merged into this table.
Download the verified data extract
BAC-01 is a compact, machine-readable extract of the published aggregate values. The files include the analysis direction, sex, population band, target band, rate, denominator, cohort window and endpoint.
Licence: the Stakhovsky Tennis extract and original presentation are available under CC BY 4.0. The source paper remains under its publisher and authors’ terms.
Frequently asked questions
What percentage of junior top-20 boys reached the ATP top 100?
In the published Brouwers et al. cohort, 43.6% of 202 male ITF junior year-end top-20 players from 1988–1999 reached the ATP top 100 by the 2008 observation endpoint.
What percentage of junior top-20 girls reached the WTA top 100?
In the published Brouwers et al. cohort, 45.7% of 175 female ITF junior year-end top-20 players from 1988–1998 reached the WTA top 100 by the 2007 observation endpoint.
Does a junior top-20 ranking guarantee a professional top-100 career?
No. In these historical cohorts, fewer than half of junior year-end top-20 players reached the professional top 100: 43.6% of the male cohort and 45.7% of the female cohort.
Can these rates predict one current junior’s career?
No. These are historical group rates from specific cohorts and observation windows. They do not estimate an individual player’s probability and should not be treated as a forecast for today’s pathway.
How to cite this review
Primary source
Brouwers, J., De Bosscher, V., & Sotiriadou, P. (2012). “An examination of the importance of performances in youth and junior competition as an indicator of later success in tennis.” Sport Management Review. https://doi.org/10.1016/j.smr.2012.05.002.
Corrections and changelog
Version 1.0, 9 August 2026: initial publication. Quantitative corrections will be dated here and reflected in both downloadable files. Report a reproducible issue to leo@stakhovskytennis.com.