Which two players are after their biggest ever wins today? What's the significance of the below picture? Every day this week wtatennis.com will bring you 10 things to look for in Istanbul - read on!
WTA Staff

ISTANBUL, Turkey - Every day we will bring you 10 things to look for on the court in Istanbul - stats, nuggets, upcoming milestones, head-to-heads - starting today with Day 1 of the round robin... read on.

(play begins at 5pm Istanbul time - watch live here)

(2) Victoria Azarenka (BLR #2) vs (6) Sara Errani (ITA #7)
Head-To Head: Azarenka leads Errani, 6-1.

Azarenka is looking for her first match win since the US Open.
~ Since reaching her fourth Grand Slam final at the US Open, Azarenka has lost her opening match at both tournaments she has played - Tokyo (to Venus) and Beijing (to Petkovic). If you include her loss in that US Open final to Serena, Azarenka comes into Istanbul on a three-match losing streak.

Azarenka is one of the best frontrunners in the game right now.
~ Since the start of 2012, Azarenka is 98-1 when winning the first set (the only loss came in the second round of Madrid this year to Makarova, 16 62 63 - her second match back after two months out).

Errani would get the biggest win of her career if she wins today.
~ The best win of Errani's career came against a No.4-ranked Radwanska at this year's French Open. She is 0-19 in her career against Top 3 players (she has pushed three of those matches to three sets).

(1) Serena Williams (USA #1) vs (8) Angelique Kerber (GER #9)
Head-To-Head: Serena leads Kerber, 2-1.

Serena could completely obliterate the single season prize money record here.
~ Azarenka set the previous single season prize money record last year - $7,923,920. Serena comes into Istanbul with $9,940,572 this year - by just taking the court today she is guaranteed to surpass $10 million, and if she goes undefeated all week and wins the title she will pass the $12 million mark.

Kerber is the only player to beat Serena in straight sets in almost 19 months.
~ Kerber's 64 64 win over Serena at Cincinnati last summer was the American's only straight set loss since Tuesday, March 27th, 2012 (when she lost to Wozniacki in Miami by the same score - 64 64).

Kerber would get the biggest win of her career if she wins today.
~ Kerber's best career win came against a No.3-ranked Sharapova at Paris [Indoors] last year. She is 0-8 in her career against Top 2 players (she has pushed the last two of those to three sets though, including holding two match points against a No.1-ranked Azarenka in the round robin here last year).

Kerber is trying to become only the third lefty ever to have multiple wins over Serena.
~ The only two lefties who have had multiple wins over Serena are Schnyder, who beat her four times, and Bammer, who beat her twice. Four others - Serna, Seles, Makarova and Kerber - have one win.

(3) Agnieszka Radwanska (POL #4) vs (5) Petra Kvitova (CZE #6)
Head-To-Head: Kvitova leads Radwanska, 4-1.

Radwanska has won two titles in Istanbul before.
~ Radwanska conquered the Istanbul Cup - a smaller clay court event - twice, in doubles in 2007 (with her sister Urszula) and in singles in 2008 (beating Dementieva in the final - the trophy pic is above).

Kvitova is looking for her 50th WTA-level match win of the year.
~ Kvitova is currently 49-21 on the year and would strike 50 with a win today (only two other players have hit 50 this year - Serena, who has 73 wins coming into Istanbul, and Radwanska, who has 56).

Kvitova has almost halved her ranking in the last few weeks.
~ Kvitova dipped to No.11 after the US Open, her first time out of the Top 10 since first breaking it 122 weeks before - but after three weeks at No.11, she got back into the elite and is No.6 this week.

More from Monday...
Istanbul Gallery: Elite Eight, All Access
Quotable Quotes: The White Group
Quotable Quotes: The Red Group
40 LOVE: Fan Fave Moments, A Taste...
WTA Live: The Draw & All-Access Hour
WTA Championships Infographic

And check out even more stats in the Match Notes - head over to the Press Center for those!