Editor's note: For two weeks, starting Dec. 8, ESPN.com is unveiling its 2014 tennis awards once per day.
Dec. 8: Men's player of year | Dec. 9: Women's player of year | Dec. 10: Top men's matches | Dec. 11: Top women's matches | Dec. 12: Top shot-makers | Dec. 15: Top shots | Dec. 16: Top tirades | Dec. 17: Most mystifying moments | Dec. 18: Top on-court moments
The familiar and the new meshed in what was a frequently surprising year on the tennis tour. Here are some of the most significant on-court developments of the season.
1. Big Four dominance diminished
The Big Four won only two of the four Grand Slams this year, but let's also not get too carried away with talk of a decline. Novak Djokovic, Rafael Nadal, Roger Federer and Andy Murray were still six of the eight Grand Slam finalists and won seven of the nine Masters 1000s. But each was a bit off. Murray's results haven't been the same since back surgery, Nadal had a string of physical problems, Federer was consistent but lacked a little extra in a few of his biggest matches, and Djokovic was up and down in a year where he had a lot happening off the court. That opened up opportunities for other players, making this season the most open on the men's tour in quite a while.
2. Serena Williams ties major company
She tripped up at the first three majors, but Serena scored her 18th Grand Slam victory and a significant piece of tennis history at the US Open, tying Martina Navratilova and Chris Evert and lifting her to fourth in the all-time ranks. Margaret Court holds the record with 24 Grand Slam singles wins.
3. Rafael Nadal nets Slam No. 14
For all the Spaniard's physical problems and defeats on clay this year, he still won his record ninth French Open title. That gave him 14 Grand Slam singles titles, tying him with Pete Sampras for second-most all time for the men.
4. Influx of injuries
They have become a regular part of the sport for players, but injuries seemed to have an even bigger impact than usual. From Nadal's back injury at the Australian Open to Federer's back injury at the Tour Finals, there was a season-long surge of physical travails. Nadal also withdrew from the US Open with a wrist injury, while Kei Nishikori withdrew from the Miami semifinals and retired during the Madrid final with hip and back problems. And though he reached the US Open final, he almost didn't play the tournament because of yet another injury issue. Victoria Azarenka's foot problem kept her off the tour for most of the season, and Juan Martin del Potro's wrist surgery did likewise. Serena had back and knee problems during various portions of the season, as did Ana Ivanovic with her hip and Sloane Stephens with her wrist.
And scores of other players such as David Ferrer, Gael Monfils and Richard Gasquet had nagging problems that took them on and off the tour, with a few even driven into retirement.
5. Men's up-and-comers
They haven't toppled the top guys consistently, but younger players such as Nishikori, US Open champ Marin Cilic, Milos Raonic, Grigor Dimitrov and Ernests Gulbis all followed through the door opened by Stan Wawrinka's Australian Open victory, crowding into the top 10. It was a significant shift from the veterans who had been filling the ranks in previous years.
6. Women's comebackers
Newer names like Simona Halep and Eugenie Bouchard had a big impact, but the women's game also saw several familiar figures move back toward their former heights. Ivanovic and Caroline Wozniacki returned to the top 10. Petra Kvitova won another Grand Slam title at Wimbledon, while Dominika Cibulkova hit her way into the Aussie Open final and Venus Williams found her way back into the top 20. But even with all this, the WTA comeback player of the year officially went to former prodigy Mirjana Lucic-Baroni, who defeated Halep at the US Open before winning her first WTA title in 16 years in Quebec City.
7. Canada’s rise
Having steadily climbed upward for a few years, Canada announced itself on the world stage at Wimbledon this year with Raonic making the men's semifinals, Bouchard the women's final and Vasek Pospisil winning the men's doubles. Bouchard also reached two Grand Slam semifinals, while she and Raonic also qualified for the WTA and ATP Finals. And with doubles veteran Daniel Nestor also still playing and one or two younger women emerging, the new Canadian presence in tennis looks set for a while.
8. The Southeast Asia boom
The Grand Slam season began with Li Na’s victory at the Australian Open, propelling her to No. 2 and the highest ranking achieved by an Asian player, and though she was about to retire by the US Open, the tournament saw Nishikori reach the final and get to No. 5, the highest for an Asian man. The growing number of players from the region comes coincidentally (or not) at a time when Asia is seeing a boom in the number of tournaments there.
9. Teenagers make their mark
Almost gone from the men's top 100 for a few years and only occasionally seen in the women's, teenagers re-established themselves this season. Nick Kyrgios pulled off one of the year's most significant performances by defeating Nadal at Wimbledon. The 19-year-old is joined by two others -- Alexander Zverev, Borna Coric -- as teenagers in the top 100. Meanwhile, Madison Keys won her first tour title at 19 and is one of four teens in the WTA top 100.
10. Switzerland takes Davis Cup
With Wawrinka establishing himself as a top player and Federer returning to the fold, Switzerland lifted its first Davis Cup by winning a fascinating final against France in front of record crowds. It can also be seen as Federer's most notable achievement of the season, giving him one of the few significant titles he had yet to capture.