There have been shock results, wonder goals, injuries, controversies and more than one managerial moan, so after the logjam of fixtures, what have we learned?

MANCHESTER CITY CAN BE STOPPED

The 3-1 victory against Watford on Jan. 2 was Manchester City's 19th win in 20 league games, but Pep Guardiola's team were prevented from beating Bayern Munich's 19-game consecutive run -- the best in Europe's major leagues -- by Crystal Palace on New Year's Eve.

But for Luka Milivojevic's failure to score a stoppage-time penalty for Palace, City would have lost and their hopes of emulating Arsenal's Invincibles would be over. That dream is still alive, but Palace showed that City can be stopped by earning a 0-0 draw, so there is hope for the rest of the league that they can still be beaten, even if they do have a 15-point gap.

MOURINHO NEEDS TO DITCH THE GRINCH ACT AT CHRISTMAS

Jose Mourinho's miserable demeanour is becoming tiresome, but the Manchester United manager took his levels of discontent to new levels over Christmas. He played the role of the Grinch perfectly by complaining about refereeing decisions, the money spent by Manchester City, the fixture computer and critical comments by former United players such as Paul Scholes. Despite all of the above, United are second in the table and eight points better off than at the same stage last season, so Mourinho needs to lighten up.

THE EMIRATES IS THE PLACE TO GO FOR ENTERTAINMENT

If you want to see goals over the Christmas period, then it might be worth heading to the Emirates Stadium next season.

Arsenal hosted two games during the festive fixture programme, with 10 goals scored in 180 minutes in the meetings with Liverpool and Chelsea.

But why so many? As a major club, Arsenal can't "park the bus" in home games against their top-six rivals, but they are also too naive defensively to put up the shutters when they go ahead, which is why they surrendered leads in both games. And nothing looks like changing any time soon, either.

GOALLESS DRAWS POINT TO FATIGUE KICKING IN

Ahead of the Spurs vs. West Ham clash, six of the 39 Premier League games played during the festive period ended as 0-0 draws.

Manchester United failed to score at home to Southampton; Chelsea could not hit the back of the net at Everton; even Manchester City hit the buffers at Crystal Palace and failed to score in a league game for the first time this season.

What is clear is that when players are running low on energy, they reduce their attacking efforts and the result is a drop in goals and entertainment levels.

REFEREES NEED A BREAK, JUST LIKE THE PLAYERS

Managers are quick to complain about players being drained by too many games over Christmas and they have a legitimate point, particularly when they are faced with two games in 48 hours, but referees are also overworked at this time of the year, so it should be no surprise that their performance levels also suffer a drop.

Match officials have made big errors in games in the past two weeks and been castigated for them, but have those mistakes been as bad as Alvaro Morata's three misses against Arsenal? Or Paul Pogba's failure to realise he was offside when touching Nemanja Matic's goal-bound strike against Southampton?

Players often get away with it, but referees are hammered, even though they are all suffering from the physical and mental strain.

MANCHESTER CITY'S PLAYERS RECOVER WELL

Kevin De Bruyne looked to be facing a long spell on the sidelines after suffering what appeared to be a nasty knee injury during the 0-0 draw at Crystal Palace on Dec. 31, but the Manchester City midfielder was back in the starting XI just 48 hours later for the home game against Watford.

The Belgian's recovery was incredible and a tribute to City's medical staff and Pep Guardiola, who have worked together to make the Etihad squad the fittest in the Premier League. City's superior fitness is a key factor in their ability to score so many crucial late goals, when opponents are unable to keep pace with them.

HARRY KANE IS AS RELIABLE AS SANTA CLAUS

Nobody delivered more at Christmas than Harry Kane, with the Tottenham forward recording the rare achievement of scoring successive hat tricks against Burnley and Southampton during the festive period.

With those six goals in three days, the England striker eclipsed Lionel Messi as 2017's top scorer in Europe's major leagues with 56, and he also broke a 22-year Premier League record set by Alan Shearer in 1995. Calendar-year records have suddenly become "a thing," but while many of them are trivial, Kane's impressive goal haul in 2017 deserves acclaim.

A GOOD DEFENDER IS NOW AS EXPENSIVE AS A GOOD STRIKER

Virgil van Dijk has a lot to prove at Liverpool after becoming the world's most expensive defender following his £75m move from Southampton.

The Dutchman was not quite as expensive as Romelu Lukaku (£90m after add-ons), but more costly than Alvaro Morata (£60m), so his fee shows that good defenders are now as hard to find as reliable goal scorers.

Manchester United were accused of overpaying when signing Rio Ferdinand for £30m in 2002, but the England defender repaid that fee several times over at Old Trafford and Van Dijk is now faced with the same challenge at Anfield.

IT REALLY IS TIME FOR A WINTER BREAK

Do we really need to stage 40 Premier League games in less than two weeks over Christmas and New Year? Do we really need to add to the fixture congestion by staging League Cup semifinals over two legs?

Man City boss Guardiola, who has also worked in Spain and Germany, where they have a break over the holidays, claimed that the current schedule will "kill" players if it is allowed to continue, but the debate has raged for years and nothing ever changes.

But if the five Premier League clubs still in the Champions League crash out before the final and if England fail again at the World Cup this summer, perhaps the message will finally get through that a winter break is desperately needed for players, referees and fans alike.