Player data updated: 2026-09-02 11:59 UTC

Koji Watanabe

JPN Age 84 Plays: Right-Handed ATP Tour years active: 1968–1972

Koji Watanabe represented Japan on the ATP Tour. In TennisDB's records, Koji Watanabe finished with a career record of 12–20 and no singles titles.

Peak singles rank

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Elo peak

1545 (16th percentile)

Singles record

12–20 (37.5%)

Singles titles

0

Records cover recorded main-draw singles results in TennisDB's ATP event archive, including credited walkovers; qualifying is shown separately below.

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ATP Matches full match log →

Koji Watanabe's recent, live, and scheduled ATP matches
Opponent	Score	Result	H2H	Match Data	Date	Round	Tournament	Category	Surface
Colin Dibley	3-6 6-8	L	H2H	Match data	Apr 2, 1972*	R16	Hong Kong	ATP 250	Hard
Charles Chang	6-3 6-0	W	—	Match data	Apr 1, 1972*	R32	Hong Kong	ATP 250	Hard
Ingo Buding	5-7 3-6 6-4 3-6	L	—	Match data	Jun 24, 1970*	R128	Wimbledon	Grand Slam	Grass
Stepan Koudelka	4-6 5-7	L	—	Match data	Jun 17, 1970*	R64	Queen's Club Championships	ATP 250	Grass
Francois Jauffret	5-7 3-6 1-6	L	H2H	Match data	May 3, 1970*	R128	Roland Garros	Grand Slam	Clay

Rivals all rivalries →

Koji Watanabe's most-played ATP rivals
Opponent	W	L	M	Last Played	H2H
Francois Jauffret	0	2	2	May 3, 1970	H2H
Colin Dibley	0	1	1	Apr 2, 1972	H2H
Charles Chang	1	0	1	Apr 1, 1972	—
Ingo Buding	0	1	1	Jun 24, 1970	—
Stepan Koudelka	0	1	1	Jun 17, 1970	—

Career Results

Koji Watanabe career results by season
Season	Age	W	L	M	Win %	Start Rank	End Rank
1968	26	7	6	13	53.9%	—	—
1969	27	4	10	14	28.6%	—	—
1970	28	0	3	3	0.0%	—	—
1972	30	1	1	2	50.0%	—	—
Career		12	20	32	37.5%	—	—

Career Results by Surface

Koji Watanabe career results by season and surface
Season	Age	Hard				Clay				Grass				Total
Season	Age	W	L	M	Win %	W	L	M	Win %	W	L	M	Win %	W	L	M	Win %
1968	26	—	—	—	—	6	4	10	60.0%	1	2	3	33.3%	7	6	13	53.8%
1969	27	—	—	—	—	2	4	6	33.3%	2	6	8	25.0%	4	10	14	28.6%
1970	28	—	—	—	—	0	1	1	0.0%	0	2	2	0.0%	0	3	3	0.0%
1972	30	1	1	2	50.0%	—	—	—	—	—	—	—	—	1	1	2	50.0%
Career	—	1	1	2	50.0%	8	9	17	47.1%	3	10	13	23.1%	12	20	32	37.5%

Advanced Stats

Koji Watanabe advanced statistics by season
Season	Age	Elo	P+	Serve+	Return+	PD	TPW%	Hard Elo	Clay Elo	Grass Elo	Set Win %	Set Margin	Dec. Set	Tiebreak	Pressure+	Schedule
1968	26	1529	104.9	—	—	—	—	—	+37	-47	51.5%	+0.03	1–3 (25%)	1–0	—	+0.48
1969	27	1471	107.4	—	—	—	—	—	+65	-43	30.8%	-1.00	1–1	—	—	+0.04
1970	28	1435	99.5	—	—	—	—	—	—	—	11.1%	-2.22	—	—	—	-0.08
1972	30	1446	104.2	—	—	—	—	—	—	—	50.0%	+1.00	—	—	—	+0.35
Career		1545	106.4	—	—	—	—	—	+48	-44	37.6%	-0.64	2–4 (33%)	1–0	—	+2.55

Tournament Results by Category

Grand Slams

Koji Watanabe Grand Slams results by season
Season	Age	AO	RG	W	W-L Win %
1968	26	—	—	R128	0–1 (0%)
1969	27	R64	R128	R64	1–3 (25%)
1970	28	—	R128	R128	0–2 (0%)
W-L		0–1 (0%)	0–2 (0%)	1–3 (25%)	1–6 (14%)

ATP 250

Koji Watanabe ATP 250 results by season
Season	Age	ASB	GST	HAM	HKG	AUS	MEL	QUE	AIX	BRI	DUS	DUT	HOB	SYD	W-L Win %
1968	26	—	R16	R16	—	—	—	—	—	R32	R16	R16	—	—	7–5 (58%)
1969	27	R16	R32	—	—	R16	R32	—	R32	—	—	—	R16	R32	3–7 (30%)
1970	28	—	—	—	—	—	—	R64	—	—	—	—	—	—	0–1 (0%)
1972	30	—	—	—	R16	—	—	—	—	—	—	—	—	—	1–1 (50%)
W-L		0–1 (0%)	1–2 (33%)	2–1 (67%)	1–1 (50%)	1–1 (50%)	0–1 (0%)	0–1 (0%)	1–1 (50%)	1–1 (50%)	1–1 (50%)	2–1 (67%)	1–1 (50%)	0–1 (0%)	11–14 (44%)

Results show the best round reached per tournament and season.

ATP Ranking History full ranking history →

Career high

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Career-high date

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First Top 100

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First Top 50

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First Top 20

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First Top 10

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Ranking History Matrix

No ranking history available.

Frequently Asked Questions

How old is Koji Watanabe?: Koji Watanabe is 84 years old, born on January 19, 1942.
Which country does Koji Watanabe represent?: Koji Watanabe represents Japan in TennisDB's ATP records.
Is Koji Watanabe left-handed or right-handed?: Koji Watanabe plays right-handed.
How many Grand Slam singles titles has Koji Watanabe won?: Koji Watanabe has not won a Grand Slam singles title.
How many Masters 1000 titles has Koji Watanabe won?: TennisDB does not group any of Koji Watanabe's titles under the modern Masters 1000 category.
What is Koji Watanabe's career win-loss record?: Koji Watanabe has a career ATP singles record of 12 wins and 20 losses (37.5%).
Which seasons of Koji Watanabe's career appear in TennisDB?: Koji Watanabe appears in TennisDB's ATP main-tour match records from 1968 through 1972.
Who has Koji Watanabe faced most often?: Koji Watanabe's most frequent opponent is Francois Jauffret, with a head-to-head record of 0–2 across 2 meetings.