Why Wimbledon is proving barren ground for women's seeds

'There are no 100 per cent winners anymore. I think every single match is competitive'

'It just shows the depth of women's tennis right now'

The top women's seeds continued to be scattered at Wimbledon on Wednesday, with Caroline Wozniacki's exit meaning five of the top eight were gone before the end of the third day.

An unprecedented 11 men's seeds and 10 on the women's side failed to make it past the first round at the All England Club as the form book was ripped up.

American Madison Keys, the 10th seed, made sure she was not amongst the casualties when she beat Thailand's Luksika Kumkhum 6-4, 6-3 on Wednesday, and there were also wins for ninth seed Venus Williams and number seven Karolina Pliskova.

But so far the women's tournament has proved wildly unpredictable -- even if seven-time champion Serena Williams has made things look easy with two routine victories.

Wozniacki's defeat by Ekaterina Makarova together with Sloane Stephen's first-round defeat on Monday means Simona Halep will remain as world number one even if she too joins the long list of title contenders to bite the dust.

"I think it just shows the depth of women's tennis right now," the 23-year-old Keys told reporters.

"I think at the beginning of a tournament, you'd never know who's going to win. There are no 100 per cent winners anymore. I think every single match is competitive."

As well as US Open champion Stephens, former Wimbledon champions Petra Kvitova and Maria Sharapova lost on Tuesday.

"It's hard. Everyone's playing hard. No one's giving you anything for free. Today I didn't get anything for free. In my first round, I didn't get anything for free," Williams, who beat Bulgarian qualifier Viktoriya Tomova 6-1 6-4, told reporters.

The 23-time Grand Slam champion remains the benchmark for women's tennis even if her long absence from the Tour means she arrived at Wimbledon with a ranking of 181.

The scramble to seize control in her absence has been intense but inconclusive and shows just how wide open the women's side of the draws has become when Williams is absent.

After the 36-year-old American won the 2017 Australian Open, five different players won the next five women's majors.

"There's just an abundance of talent but it's very unpredictable at the top," three-time Wimbledon champion Chris Evert said on the eve of Wimbledon where she is working as a summariser for broadcaster ESPN.

"There's 10 women that can win a Grand Slam. It's unpredictable. It's still wonderful to watch."

Halep, who moved easily into round two, said seeds were even more vulnerable at Wimbledon where players often arrive with little grasscourt practice.

"Here on grass, you don't know what to expect," the Romanian said. "Some players can play best tennis. The top players can play a little bit less. You never know."

The men's draw has already lost sixth seed Grigor Dimitrov, 10th seed David Goffin and number seven Dominic Thiem, the latter due to an injury during his match.

French 18th seed Lucas Pouille was cast aside on Wednesday by Austrian qualifier Dennis Novak, ranked 152 places below him.

Yet there is still more predictability at the top of the men's game with Federer and Rafael Nadal sharing the last six Grand Slam titles and Marin Cilic reaching two finals.

Former world number one Mats Wilander believes the men's game could use a few more seismic shocks and thinks a reduction to 16 seeds from 32 next year could help.

"I think (the seeds going out) it's way more positive than negative for women's tennis," Wilander, working as Eurosport's lead analyst at Wimbledon, told Reuters.

"I hope that men's tennis goes that way where we see more upsets. It's great to follow Federer and Nadal, but I think 16 seeds would shake up the men's draw."