The ladies semi-finals take place tonight with the action starting at midnight UK time, and our tennis columnist, Dan Weston, previews the two matches...
"In 2017, Keys has held serve 81.4% on hard courts, giving her a 2.6% advantage over her compatriot Vandeweghe, who has done so 78.8% of the time, but Keys' return data also gives her a 6% edge, having broken opponents 34.5% of the time compared to Vandeweghe's 28.5%."
Pliskova out as Keys becomes favourite
Wednesday night's two remaining quarter-finals saw straight set victories for Coco Vandeweghe and Madison Keys, with Vandeweghe ousting the outright favourite, Karolina Pliskova in a tight two-setter with few breaks, and Keys ending the journey of the qualifier, Kaia Kanepi, in relatively straightforward fashion.
With the previous outright favourite Pliskova now out, Keys' victory has now propelled her to the new tournament favourite, at [2.82], with all four players - all American - priced at [6.4] or below.
Certainly, Keys has the best stats left in the event by a reasonable distance, and I'll discuss this in a little more detail later in this preview.
Veteran Williams correctly priced for clash with Stephens
However, prior to Keys' clash with Vandeweghe is an intriguing match-up between Venus Williams and Sloane Stephens. I wrote on Tuesday that I felt Williams would be under-rated in the event of a semi-final with Stephens, but the market has seen sense and has priced the 37-year-old veteran at [1.67] at the time of writing.
My model pretty much agreed with this, with Venus having a 3.4% projected hold advantage over Stephens, and there are also several other factors worth mentioning.
Stephens unbeaten in deciding sets following return to tour
Firstly, Stephens, with her victory over Anastasija Sevastova, improved her final set record to 7-0 following her return to tour from a long-term injury and it's difficult to establish whether this is an absurdly good fitness level and clutch play, or positive variance. I'd probably lean towards the latter at this point in time, although the truth could easily be somewhere in between.
Secondly, Williams boasts much better break deficit recovery stats than her countrywoman, and on this basis should be able to pressurise Stephens more if a break down than Stephens should be able to do to her.
Despite these comments, with no pre-match value in the opening semi-final, I'll move on to the second semi-final, which looks likely to be an extremely serve-orientated encounter between Keys and Vandeweghe.
Serve and return edges give Keys value
Currently, Keys is [1.70] on the Exchange, which looks a touch of value with my model making her [1.57] to progress to Saturday's final, and her projected hold percentage, as the best server in the event against a worse than average returner, is almost 90% for this match - a figure virtually unheard of for a women's match.
In 2017, Keys has held serve 81.4% on hard courts, giving her a 2.6% advantage over her compatriot Vandeweghe, who has done so 78.8% of the time, but Keys' return data also gives her a 6% edge, having broken opponents 34.5% of the time compared to Vandeweghe's 28.5%.
With Keys playing well in the event, and with a considerable advantage across serve and return, I feel she does represent some value tonight, and I'd envisage that she'd be a favourite against either of Williams or Stephens in the final as well.
Back Madison Keys at [1.70] to beat Coco Vandeweghe
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