1991 - Made first appearance in Tour qualifying at San Diego (as WC); played first Tour main draws, reaching 2r at Schenectady (as WC) and falling 1r at US Open (as WC).
1992 - Played five Tour main draws, best results being 2r at Miami and US Open (as WC at both; l. to SÂ nchez-Vicario at both); fell in qualifying at Roland Garros and Wimbledon; won one doubles title on ITF Circuit.
1993 - Breakthrough season; won first title at Lucerne; made Top 100 debut on January 18 (rose from No.135 to No.99), Top 50 debut on March 8 (rose from No.73 to No.48) and Top 20 debut on September 13 (rose from No.24 to No.20); turned pro on February 22 (after Indian Wells); a week later had first Top 10 win at Delray Beach (No.5 Sabatini); played all four majors in a year for first time; reached first Grand Slam 4r at US Open (l. to Sabatini).
1994 - First Top 10 season; won two titles at Brisbane and Lucerne; reached first two Grand Slam QF, at Australian Open (l. to Graf) and Wimbledon (l. to MartÂ¡nez); had three Top 10 wins early in season before making her own Top 10 debut on May 9 (rose from No.12 to No.10); runner-up at first Tour Championships (l. to Sabatini); won two doubles titles and qualified for Tour Championships in doubles (w/Raymond; l. first match).
1995 - Strong start to season but inconsistent second half led to non-Top 10 finish; won one title at Strasbourg; runner-up twice, at Sydney (l. to Sabatini) and Tokyo [Pan Pacific] (l. to Date Krumm); best Grand Slam was QF at Australian Open (l. to MartÂ¡nez); spent all but one week of season in Top 10 but dipped out on year-end rankings after falling 1r at Tour Championships (l. to Sabatini); won four doubles titles.
1996 - Another Top 10 season;; won three titles at Strasbourg, Olympics (d. four Top 10 players en route without dropping a set; d. SÂ nchez-Vicario in final, having been 0-5 against her) and Los Angeles (d. Graf in SF for first win over a reigning No.1; only win over Graf when she was No.1); runner-up at Sydney (l. to Seles 46 76(7) 63; held mp second set); best Grand Slam was QF at Roland Garros (l. to MartÂ¡nez); made Top 5 debut on September 30 (rose from No.6 to No.5); at Tour Championships, reached QF (l. to Graf 64 76(11); led 5-2 second set w/5sp in tie-break); won five doubles titles (incl. Roland Garros and Tour Championships w/M.Fernandez).
1997 - Finished season at No.3 (behind Hingis, Novotna); won six titles at Oklahoma City, Indian Wells, Amelia Island, Atlanta, ZÂrich and Chicago; runner-up twice, at Los Angeles (d. Hingis in SF, the world No.1's second loss in 57 matches of season at that point; l. to Seles 57 75 64 in final, having held mp in second set) and Philadelphia (l. to Hingis); fell early at first three majors, with 4r losses at Australian Open (l. to Po-Messerli) and Roland Garros (l. to eventual champion Majoli 57 64 62; led 75 40) and 2r exit at Wimbledon (l. to Chladkova) but reached first Grand Slam SF at US Open (l. to Hingis); crept up Top 10 all season, making Top 5 debut on September 30 (moving from No.6 to No.5), rising to No.4 on October 20 (after ZÂrich; would stay inside Top 5 uninterruped until April 21, 2002), to No.3 on November 10 (after Chicago) and to No.2 on November 17 (after Philadelphia); dipped to No.3 on year-end rankings after falling 1r at Tour Championships (l. to Fernandez 76 third set, having held mp); won seven doubles titles (incl. US Open and Tour Championships w/Novotna) and rose to No.1 in doubles on October 20 (for two weeks).
1998 - First No.1 finish in season highlighted by sizzling summer hardcourt form, winning four of five events at Stanford (d. Graf in SF and V.Williams in final), San Diego (d. Seles in SF and Pierce in final), Los Angeles (d. Seles in SF and No.1 Hingis in final) and US Open (did not drop a set en route; d. V.Williams in SF and No.1 Hingis in final; won title on mother's birthday); only loss in summer came at New Haven (l. to Graf in SF, snapping 13-match win streak); won six titles in total, first coming at Tokyo [Pan Pacific] (d. No.1 Hingis in final) and in fall at ZÂrich (d. V.Williams in final); runner-up four times, at Indian Wells (l. to Hingis), Filderstadt (l. to Testud), Philadelphia (l. to Graf) and Tour Championships (l. to Hingis in 4s); QF or better at other three Grand Slams, with SF at Australian Open (l. to MartÂ¡nez) and Roland Garros (l. to SÂ nchez-Vicario) and QF at Wimbledon (l. to Tauziat); became eighth No.1 player in history on October 12 (after Filderstadt; ended Hingis' 80-week reign) and held top spot until February 1999; won six doubles titles (incl. Tour Championships w/Zvereva) and spent 13 more weeks at No.1 in doubles (none simultaneously w/singles No.1).
1999 - Finished season at No.2 (behind Hingis); won seven titles, most notably Wimbledon (d. Graf in final; did not drop a set en route to second Grand Slam singles title) but also at Sydney (d. Graf in SF and Hingis in final), Madrid, Stanford (d. V.Williams in final), Tokyo [Princess Cup] (d. Seles in final), Philadelphia (d. V.Williams in SF and Hingis in final) and Tour Championships (d. Hingis in final); runner-up at New Haven (l. to V.Williams); QF or better at other three majors, with SF at Australian Open (l. to Mauresmo 46 75 75; led 4-2 third set) and US Open (l. to S.Williams) and QF at Roland Garros (l. to Graf); first stint at No.1 came to an end (17 weeks between October 12, 1998 and February 7, 1999); second stint at No.1 came and went (five weeks between July 5, 1999 and August 8, 1999); won four doubles titles (incl. Wimbledon w/Morariu) and spent 13 more weeks at No.1 in doubles (none simultaneously w/singles No.1); withdrew prior to Miami QF vs. Graf w/left wrist sprain (suffered in practice); same injury caused withdrawals from Hilton Head, Fed Cup, Filderstadt and ZÂrich.
2000 - Finished season at No.2 (behind Hingis); won four titles, most notably Australian Open (d. Hingis in final to end her 27-match, three-title win streak there; did not drop a set en route to third Grand Slam singles title); other titles came at Indian Wells (d. Hingis 46 64 60 in final; was down 64 42), Linz (d. V.Williams in final) and Philadelphia (d. Hingis in final); runner-up seven times, at Sydney (l. to Mauresmo), Miami (l. to Hingis), Wimbledon (l. to V.Williams), Stanford (l. to V.Williams), Los Angeles (l. to S.Williams), US Open (d. Clijsters, Henin and S.Williams en route to final; l. to V.Williams) and ZÂrich (l. to Hingis); strong start to season (24-1; only loss was to Mauresmo) helped her return to No.1 for two short stints (five weeks between April 3 and May 7; one week between May 15 and May 21) but dipped back to No.2 by year's end; on April 17, became the fourth player (now five) in history to hold No.1 in singles and doubles simultaneously (for three weeks between April 17 and May 7; Navratilova, SÂ nchez-Vicario and Hingis preceded her and Clijsters later on); struggled with injury in clay court season, withdrawing from Amelia Island and Hilton Head (w/left ankle injury) and prior to Rome 3r and Madrid (w/lower back strain); suffered back spasms during 1r loss to Van Roost at Roland Garros (her only pre-final loss of Grand Slam season); fell 1r at Tour Championships (l. to Dementieva 36 76(7) 64; held mp in second set); won one doubles title.
2001 - Second No.1 finish after strong start and finish but injury-plagued clay court season; three finals in early stages, winning Tokyo [Pan Pacific] (d. Hingis in final) and Scottsdale and finishing runner-up at Sydney (l. to Hingis); suffered right knee bone bruise in Miami QF, retiring then missing all events in April and May (incl. Roland Garros); made impressive return in grass season, winning Eastbourne and reaching SF at Wimbledon (l. to V.Williams); strong summer hardcourt season incl. title at Los Angeles and runner-up at Stanford (l. to Clijsters) and New Haven (l. to V.Williams); after QF exit at US Open (l. to S.Williams) had 15-match win streak that brought fifth, sixth and seventh titles of year at Filderstadt (d. Henin in final), ZÂrich (d. new No.1 Capriati en route) and Linz, and took her to Tour Championships final (where she d. Clijsters 76 third set in SF to clinch year-end No.1 ranking by 10 points over Capriati; had injured right knee in last two points of SF and withdrew prior to final vs. S.Williams); with run to final, began fifth stint at No.1 on November 5; won two doubles titles; withdrew from MontrÂ‚al w/left wrist injury.
2002 - Finished season at No.12 after missing first half of season w/injury; had arthroscopic knee surgery on January 11 to correct full thickness cartilage defect and spent nine weeks on crutches; fifth stint at No.1 (10 weeks between November 5, 2001 and January 13, 2002) came to an end on January 14 (to Capriati); withdrew from all events, incl. first three majors of year; played first matches back in Fed Cup (USA vs. Israel) then returned to Tour at Stanford; SF or better at all five events of summer, with SF at Stanford (l. to Clijsters 46 64 62; led 64 42) and San Diego (l. to V.Williams), runner-up at Los Angeles (l. to Rubin 57 76(5) 63; served for match at 75 54) and New Haven (l. to V.Williams) and SF at US Open (l. to S.Williams 63 75; led 5-2 second set w/3sp); reached two more finals in fall, finishing runner-up at Moscow (l. to Maleeva) and ZÂrich (d. Clijsters and Henin en route to final; l. to Schnyder 67(5) 76(8) 63, having held 2mp second set); fell 1r at Tour Championships (l. to Seles 36 76(6) 63, having held 7mp; had won nine straight matches against Seles); finished outside Top 10 for first time since 1995.
2003 - Finished season at No.5 (behind Henin, Clijsters, S.Williams and Mauresmo); won one title at Tokyo [Pan Pacific] (d. Seles in final); runner-up five times, at Sydney (l. to Clijsters), Indian Wells (l. to Clijsters), Amelia Island (l. to Dementieva 46 75 63; led 62 42), Los Angeles (l. to Clijsters) and New Haven (ret. vs. Capriati w/left foot injury); in Grand Slams, reached 4r at Australian Open (l. to Henin 75 57 97; had rallied from 75 41 down and led 4-1 third set before falling), 4r at Roland Garros (ret. vs. MartÂ¡nez w/left foot injury), QF at Wimbledon (l. to V.Williams) and SF at US Open (l. to Clijsters); ret. in Miami 4r mw/right hamstring strain; was bothered throughout season by left foot injury (Morton's neuroma) and had surgery on October 15 following only post-US Open event played at Filderstadt (l. to Bovina in QF); qualified for Tour Championships for 10th straight year but withdrew following surgery; won three Tour doubles titles.
2004 - Third No.1 finish in season highlighted by seven titles, four of which came in season-best 22-match win streak at Stanford (d. V.Williams in final; had lost last six meetings), Los Angeles (d. S.Williams in final; had lost last five meetings), San Diego and Cincinnati (win streak snapped in US Open SF; l. to Kuznetsova, having been hampered by left hip strain); three other titles came at Tokyo [Pan Pacific], Amelia Island and Filderstadt; runner-up twice, at Indian Wells (l. to Henin) and Strasbourg (l. to Schaul); in first three Grand Slams, reached QF at Australian Open (l. to Henin 75 63; led 4-0 in first set w/3sp), 4r at Roland Garros (l. to Dementieva 61 63; hampered by right knee injury) and SF at Wimbledon (l. to Sharapova 26 76(5) 61; led 62 31); first player to qualify for Tour Championships, falling in RR stage w/2-1 record (d. Dementieva and S.Williams; l. to Myskina); with run to Moscow SF, began sixth stint at No.1 on October 18 (144 weeks since she was last No.1, at the time longest gap between spells at No.1 since Evert returned to No.1 in 1985; since surpassed by S.Williams in 2008); withdrew prior to Sydney SF w/right shoulder injury, from New Haven w/left wrist tendonitis and from ZÂrich w/influenza.
2005 - Fourth No.1 finish in season highlighed by six titles at Dubai, Amelia Island, New Haven, Bali, Filderstadt and ZÂrich (first time to win a title from mp down; saved 2mp down 63 54 to Hantuchova in 2r); runner-up four times, most notably at Australian Open (l. to S.Williams 26 63 60; lost nine games in a row from 62 33 up) and Wimbledon (l. to V.Williams 46 76(4) 97; served for match at 64 65 and held mp at 5-4 third set; at 2hrs, 45mins was longest Wimbledon ladies' singles final ever), but also at Tokyo [Pan Pacific] (l. to Sharapova) and Indian Wells (d. Sharapova 60 60 in SF; l. to Clijsters); QF at other two majors, at Roland Garros (d. Clijsters in 4r; l. to Pierce) and US Open (l. to Dementieva 61 36 76(6); held mp at 6-5 in tie-break); qualified for Tour Championships, reaching SF w/2-1 RR record (l. to Sharapova in RR; l. to Pierce in SF); injuries stopped her in other three events - withdrew prior to Sydney QF w/bronchitis, ret. in Charleston QF vs. Henin (w/right hip strain) and in Stanford 2r vs. Groenefeld w/low back strain; low back strain caused withdrawals from San Diego, Los Angeles and Beijing; withdrew from Philadelphia w/influenza; sixth stint at No.1 came to an end (44 weeks between October 18, 2004 and August 21, 2005; Sharapova took over); seventh stint at No.1 came and went (two weeks between August 29 and September 11; Sharapova took over); began eighth stint at No.1 on October 24); finished year at No.1 four fourth time (also 1998, 2001 and 2004), fourth player in Tour history to achieve the feat (after Evert, Navratilova and Graf); also became third woman to surpass $20 million in career earnings (after Navratilova and Graf; has since been joined by Hingis and Williams sisters).
2006 - First non-Top 20 finish since 1992 after injury-marred year; went 8-3 in first three events, reaching QF at Australian Open (l. to Henin), SF at Dubai (l. to Sharapova) and 4r at Indian Wells (l. to Hingis); withdrew from Amelia Island, Roland Garros, Wimbledon, Stanford and San Diego w/back injury; returned to Tour in summer, going 13-5 in five events, losing comeback match at Los Angeles (l. to Stosur) but finishing runner-up at New Haven (d. Mauresmo in QF for 15th win over a reigning No.1, now 15-18 lifetime; ret. vs. Henin w/right shoulder strain), QF at US Open (l. to Henin), SF at Bali (l. to Kuznetsova) and QF at Beijing (l. to Mauresmo); eighth and most recent stint at No.1 (14 weeks between October 24, 2005 and January 29, 2006) ended on January 30 (after Australian Open; Clijsters took over); career tally is now 98 total weeks; on August 21 (after Los Angeles), dipped from No.10 to No.11, first time outside Top 10 since January 12, 2003, also first time in history no American was in Top 10; won one Tour doubles title; also withdrew from Tokyo [Pan Pacific] (w/left ankle injury); announced pregnancy in December and indefinite leave from the Tour.
2007 - Stellar return to Tour following 11-month absence while having first child; went 13-1 in three singles events, winning Bali (d. Jankovic en route to final, then d. Hantuchova), SF at Beijing (d. Dementieva en route; l. to Jankovic) and winning QuÂ‚bec City (d. Zvonareva in SF and Vakulenko in final); at No.234 in Bali, was fourth-lowest-ranked player in history to win a Tour singles title (after No.579 Widjaja at 2001 Bali, No.285 Zuluaga at 2002 BogotÂ and No.259 Paszek at 2006 Portoroz); going into Bali, hadn't played a singles match for 51 weeks (at 2006 Beijing); was second mother to win a Tour singles title in 2007 (after Bammer at Pattaya City), first season in history where two mothers won Tour singles titles; returned to Top 100 on November 5 (after QuÂ‚bec City; rose from No.126 to No.73) and finished in Top 100 for 15th straight year; first match back came in doubles - having given birth to child, Jagger Jonathan Leach, on Sunday, June 10, announced on July 18 her return to the Tour, beginning with playing doubles at New Haven in August (w/Raymond; l. 1r to Black/Huber).
2008 - Sixteenth straight Top 100 season; won 54th and 55th Tour singles titles at Auckland (d. Rezai in final) and Memphis (as No.4 seed, d. No.5 seed Govortsova in final); now tied for No.7 all-time in Tour singles titles won (w/Wade); SF at Amelia Island (as No.16 seed, d. No.8 seed Szavay en route; withdrew prior to match vs. top seed and eventual champion Sharapova w/viral illness); QF at Indian Wells (as No.24 seed, d. No.6 seed Bartoli en route; ret. vs. No.3 seed Jankovic w/back injury); pre-QF exits in four other events, falling in 2r of Australian Open (l. to No.5 seed and eventual champion Sharapova), 4r of Miami (as No.32 seed, d. No.2 seed Ivanovic en route, falling to No.13 seed Safina; win over world No.2 Ivanovic was best win of comeback in terms of ranking), 2r of Wimbledon (as No.25 seed, withdrew prior to match vs. Dulko w/right knee injury) and 3r of US Open (as No.23 seed, l. to No.12 seed Bartoli); member of American Fed Cup team that d. Germany 4-1 in World Group 1r (went 2-1); withdrew from Roland Garros w/personal reasons and from Eastbourne, Stanford, Los Angeles, Olympics and Luxembourg w/right knee injury; won 37th Tour doubles title at Memphis (w/Raymond); played doubles at Olympics, reaching QF (w/Huber; l. to Medina Garrigues/Ruano Pascual); became No.1 all-time prize money earner on January 28 (after Australian Open; surpassed Graf) and became first player in Tour history to surpass $22 million on April 7 (after Miami).
2009 - Announced in December 2008 she is expecting second child; withdrew from 2009 Australian Open and will be off the WTA indefinitely.
2010 - Made return to WTA in doubles at Stanford, winning 38th WTA doubles title (w/Huber); reached QF at San Diego (w/Huber - l. to Mattek-Sands/Yan).
2011 - Did not play.
2012 - Did not play.
2013 - Did not play.