Serena Williams
Serena Williams has her eyes focused on further glory in 2016. Getty Images

Because of the way it ended, the true scale of Serena Williams’ achievements in 2015 has perhaps gone under appreciated. And it is hugely unfortunate and greatly unjust that the moment from her incredible season that will live longest in the memory is one of only three defeats she suffered. That crushing, emotional loss to Roberta Vinci in the semifinals of the U.S. Open was one of the greatest upsets of all time, and dramatically prevented Williams from claiming the Calendar Grand Slam that looked to be in her grasp.

That the American didn’t play again following her exit in New York no doubt reflected the huge physical and psychological toll her pursuit of just the fourth Calendar Grand Slam in women’s tennis history, and the first since 1988, had taken. But it has also surely helped provide time to appreciate what she did accomplish -- something that will have been helped by her landing an array of awards, including Sports Illustrated’s Sportsperson of the Year.

The extended layoff should also leave her raring to go at the start of 2016. Although the task of bouncing back after coming so close to such an incredible feat would be tough for any sportsperson, Williams has plenty still to motivate her, even at the age of 34 and having already etched her name in the tennis history books. Most obviously there is the opportunity to go for the Calendar Grand Slam once again. Still a dominant No. 1, it would be dangerous to bet against her. And Williams has already confirmed that winning all four Majors will be her primary goal next year.

“It is, obviously,” she said earlier this month, according to the Associated Press. “I've never done it. We'll see. I'm not putting any pressure on it. I'd have to have a good year in the beginning, win Australia, win French. I've only won the French three times, so that's going to be a little difficult to do.”

But even without that ultimate goal, there are plenty of notable feats that Williams can accomplish over the next 12 months. Indeed, history could be made at next month’s Australian Open, where a victory would give Williams her 22nd Grand Slam title and take her level with Steffi Graf for the most ever in the Grand Slam era. She would also then be just two behind Margaret Court for the all-time record.

Given that Williams has won the Australian Open six times -- a record in the Open era -- she goes into Melbourne as an overwhelming favorite to take home the trophy. According to the oddsmakers, her biggest threat will come from Maria Sharapova. Yet Williams has beaten the Russian star on 17 straight occasions, dating back to 2004. Instead, the player Williams is likely to be most wary of is Victoria Azarenka. The Belarussian has had a disappointing few years as she has struggled to maintain her fitness, but she has won twice in Australia, and at last year’s Wimbledon gave Williams an almighty test in one of the matches of the year.

As Williams hinted, the toughest Grand Slam for her to win is likely to be the French Open, where her power is dulled and the likes of world No. 2 Simona Halep should be more of a threat.

In terms of the rankings, though, Williams is nearly 4,000 points ahead of Halep, making it difficult to see her relinquishing her grasp on the top spot any time soon. And having on Monday celebrated 150 consecutive weeks at No. 1, she now has yet another record in her sights. Already sitting third on the all-time list, she is now just 36 weeks shy of Martina Navratilova’s record mark for successive weeks on top of the rankings.

It may be hard to match the drama of 2015, but Williams has every chance of making 2016 another year to remember.