Don't forget about Venus: Why big sister can beat Serena Williams

Just to further highlight his mastery in every thing he says and does, it was Roger Federer who provided the clearest pearl of wisdom in the first week of Wimbledon on a topic he probably knows very little about. As every player was forced to discuss Serena Williams after their own successes, Federer skipped around the question initially to offered up a command of his own in response. “Don't forget about Venus,” he warned.

Don't forget about Venus. That seems quite obvious, but throughout the years of this unprecedented Williams story, it has been so easy to do just that. It was father Richard who set the tone long ago when there was only one senior professional tennis player from the Williams family. Asked by a reporter about his superstar daughter, he offered up one of his many famously prophetic quotes in return, claiming the still unknown younger sister would be even greater because she was “better, badder and meaner".

Since then, it has become increasingly easy to momentarily forget that there is another. When Venus built up a solid young career and her first slam looked imminent, Serena arrived like a thief in the night to steal her maiden title at 17 years old. When Venus finally broke through and dominated tennis between 2000 and 2001, Serena cackled as she responded by winning four slams in a row the following year, vigorously rubbing salt into her sister's weeping wounds by beating Venus in the final of every single one.

The list goes on forever. Since 2012, the large distance between the achievements of Venus and Serena has rapidly expanded to the size of an infinite black hole. From holding fewer than double her sister's slam count before Wimbledon 2012, Serena is now one from her 21 count tripling Venus' 7.

To be thorough, Serena began her first two tournaments of this three year gold rush by wiping out the only two distinctions Venus retained over her sister. First, the woman who claims to detest grass more than any other surface, equalled her sister with five Wimbledon triumphs after her victory that year. Three weeks later, she returned to Wimbledon to capture her first singles Olympic gold medal at London 2012, levelling with Venus' gold 12 years earlier in Sydney.

But, again, don't forget about Venus. This week, the attention has again been lavished on Serena. When she won easily, it was about the prospect of her securing the Grand Slam. When she almost lost to Heather Watson, the intensity of the spotlight only increased tenfold. But as Serena toiled into a third set against the home favourite, out on Court 2, Venus calmly wrapped up her third round to book her own spot in their fourth round match to come. The court placement in itself actually served as another example of how Venus has been forgotten, as the five-time champion of this event is yet to even glimpse either of the top two courts this year.

But away from the attention, Venus has been hard at work. She dropped one of the most brutal double bagels ever seen against her countrywoman Madison Brengle in her opening match, and has cruised since then. What she has showcased looks even better than the scores – she is serving brilliantly, her movement is making a mockery of the fact that she is 35 years old and she is hitting impressively off the ground. She is playing like she owns the courts and surface, which she of course does.

Needless to say, Venus Williams is far removed from her glory days. She is 35 years old, she has been forced to battle an autoimmune disease that can leave her entirely exhausted in a sport that is impossible to play without such energy, and though her ranking of 16th is an incredible achievement for those reasons, it sure isn't number one.

But she has already been close enough in her two biggest tournaments off clay this year to think about what could happen. After winning her first tournament of the year, defeating Caroline Wozniacki in Auckland, an exhausted Venus lost in the quarter-finals of the Australian Open when she really should have reached the semi-finals. Months later in Miami, Venus looked to be playing some great tennis and the path was open to another big final. Then, after an incredible first set in her quarter-final against Carla Suarez Navarro, she bizarrely collapsed.

None of these missed chances and self sabotage are anything new for Venus. In fact, Williams' start to this season, a period that is traditionally her weak half of the year, showcased more encouraging signs than in many of her Wimbledon-winning years. And it's usually on these lawns that she brushes all the remaining obstacles aside and everything finally clicks.

There is every chance that, after the Watson scare, Serena will have counted her blessings, learnt her lesson and she will show up ready to storm through. But this hasn't happened at all in recent months. Throughout this run, Serena has been more mentally rigid than in over a decade, but she has been found lacking in the fairly important aspect of playing tennis. After barely surviving so many tight matches between France and London, it is clear that the right person with the right weapons and experience could finally make her pay for her sloppiness.

And so Monday presents a strangely brilliant opportunity for Venus Williams. She may be older, she may be burdened with illness and she may be facing the world number one. But this, it seems, is it. It is a meeting of olympic-sized consequences for her sister and herself. On one hand, this appears the greatest shot anyone has to stop Serena before she reaches the late stages of the draw where she is usually unstoppable. In the process, removing perhaps her last opportunity to win the Grand Slam. Meanwhile, with this form and in this condition, it may just be the elder Williams´ final opportunity for another big, glorious run.

She has her game, she has her courts, she has the 11 victories over her sister and she has their most recent meeting last year in Montreal where, in surreal scenes, she triumphed over Serena in a brilliant performance. The only thing left to see is if Venus has the wherewithal to go out and, at least for one last time, produce something that no onlooker could possibly forget.