In the "Christmas truce" of 1914 were there any football (soccer) matches between British and German troops?

This depends a bit on the definition of "match": modern rules 90 minutes kicking, level playfield, three referees, 11 players on each side, two nicely timbered goals, etc. Most popular accounts now seem to imply this. If it's that, then it's a resounding no.

But bringing a ball to the trenches (in itself quite an astonishing thing to do?) and playing with it going about between British and German soldiers?

That occured. Multiple times. Although not nearly as often in reality as later reported. And much less organised as "match" implies. Even one 'real match' (or very few) might have occurred, against all unlikeliness. But most likely more like older forms of football. The important thing to distinguish here is that they did play, with 'a football', of whatever material, sometimes. And that they were really eager to do so on a very broad level. For the participants during the events and even more so later, in the aftermath of the war. Soldiers wanted to play. And people wanted to believe that they did. As time progressed, that desire apparently grew ever stronger despite the evidence for that not being able to match the pace.

What did not occur – despite being now almost the norm in cultural memory – is the practice of widespread organised football matches.

Despite being really one 'nice thing' about the war, and in itself a single occurrence would be quite remarkable, the representation in memory is not 'untrue' but somewhat inflated.

So, yes, "the football matches during the Christmas Truce" are one of the myths surrounding the trenches. But at the same time that 'myth' is certainly based on quite a solid foundation, compared to others.

A re-enactment of the 1914 Christmas Truce in Ploegsteert, Belgium (AP) Christmas Day truce 1914: Letter from trenches shows football match through soldier's eyes for first time, Independent, 2014

His letter to his “dearest mother”, describing the famous moment former enemies risked their lives to walk out into no-man’s land to wish each other a happy Christmas and play football, has been released by Royal Mail with his family’s permission.

This is supposedly a real picture from 1914:

Dokumentiert: Briten und Deutsche trafen sich während des Ersten Weltkriegs im „Weihnachtsfrieden“ 1914 auf improvisierten Fußba (Foto: pr)

_{Comment to that picture, also used on the cover of a book cited later here: it may be from 1914. But I fail to see German soldiers in the picture, the field doesn't look like no-man's land and the people are quite scantily clad for the expected temperatures… This picture is copied thousands of times across the net, only rarely source attributed. Sometimes the source is given as 'Imperial War Museum'. Nice. Only that I can not find it there.
If anyone can contribute to identification or other details, please do so.}

From another account:

In addition to the exchange of food and souvenirs, another standard element of many individual truces was a proposal to engage in a football match. Considering that both the British and Germans were enthusiastic footballers, and that international fixtures had been recently regulated after the creation of the Fédération Internationale de Football Association (FIFA) in 1904, it is hardly surprising that the thoughts of the opposing troops would turn to the possibility of a game. Although in most cases a proper match was impractical for many reasons, including lack of a ball and a suitable patch of ground, it was apparently frequently suggested. Wedderburn-Maxwell, for example, wrote that the two sides “wanted to have a football match yesterday afternoon but couldn’t get a ball.”

On Christmas morning, the officers return to No Man’s Land and coordinate the burial of the dead. After the bodies are interred and a service is read over the graves, fraternization resumes with a hastily arranged football match and card playing, and there is even a juggler entertaining the troops. The next morning Horstmayer, the German officer, walks over to the French line.

British and German soldiers met in No Man’s Land, gossiped, exchanged cigarettes. In some places they played football. They met again the next day. Then, after strong rebuke from headquarters, ring gradually started again.

No one was punished for participation, and very few of those who took part allowed the event to alter their view of the war. The truce did include shared drinks and spontaneous games of football, but it also featured solemn burial parties and moments of treachery. Furthermore, the manner in which the details of the truce were accepted by the British public demonstrates that the home front was ignorant neither of the conditions on the Western Front nor the attitudes of the soldiers who served there. Consequently, the holiday armistice, in itself a fascinating and complex episode, also serves as a means of achieving further insight into the experiences and attitudes of soldiers on the Western Front, the views of the British public toward the war, and the way the discourse of the war has evolved over the past century. As a result, the 1914 Christmas truce, an event that at first glance appears to confirm the popular interpretation of the First World War, can be used to challenge that view and contribute to a more complete understanding of both the conflict and the development of the war’s orthodox narrative.

Spent a very quiet Xmas day.
Troops fraternized with enemy on 6th Div. front and held a concert and football match. Pork for dinner.
—J. S. Fenton, 2nd Field Company Royal Engineers, diary entry for 26 December 1914
(Chapter: “a Great day with our enemies”)

While all these accounts provide details that could be found in certain of the 1914 holiday truces, they tend to treat the armistices as more consistent and h*m*genized than they actually were. The Christmas truce was certainly a moment of “peaceable behavior,” as Gilbert notes, but participation was motivated more by the holiday season than by a desire to lay down arms. Certainly the cease-fire was inspired partly by the idea that the enemies opposite were men like themselves, but few soldiers participating in the truce would have believed that, by ghting a war that they perceived as necessary, they were not behaving decently the remainder of the time they spent in the trenches. The football match that De Groot claimed was inspired by the atmosphere of the truce did occur, but it was the exception rather the rule.

Terri Blom Crocker: "The Christmas Truce. Myth, Memory, and the First World War", University Press of Kentucky: Lexington, 2015.

The German Wikipedia concludes:

In a letter published in the Times, the German lieutenant Niemann explained that in his sector at Frelinghien-Houplines a football match had been played which had run out 3:2 for the Germans - a symbol of Christmas peace which contributed to the formation of legends. However, the truth content can no longer be verified today. What is certain, however, is that there was an unorganised kick between the opponents, but that it was not played on a goal, let alone with a referee.

The Football Times:

The same book shares an account from the German perspective as Lieutenant Johannes Niemann of the Saxon 133rd Regiment told of a football match between the Germans and the Argyll and Sutherlands Highlanders deployed in the BEF: “A Scottish soldier appeared with a football which seemed to come from nowhere and a few minutes later a real football match got underway. The Scots marked their goal mouth with their strange caps and we did the same with ours. It was far from easy to play on the frozen ground, but we continued, keeping rigorously to the rules, despite the fact that it only lasted an hour and we had no referee.
Source: If Only For A Day: The Christmas Truce Of 1914

So it seems that these matches did in fact occur, well, some of them, but were much more often only proposed or reported as rumours, most accounts attesting the matches as occurring in "that other unit". It is therefore not quite right to assume that within the hour peace broke out along the lines and almost a league being devised ad hoc to 'shoot it out on that kind of field'.

Kicking around and playing did occur; a real match is attested for very few times and quite unlikely for most, later reports. An organised match in our current sense of the word and how some have been reported: remains uncertain.

Most participants on both sides of the truce probably regarded it as an unexpected holiday and some availed themselves of the opportunity to play their favourite game. […]

Klemm received a cap badge from a British soldier and noted ‘everywhere you looked the occupants from the trenches stood around chatting to each other and even playing football’. Niemann, as described above, recollected that later, a Scottish soldier brought out a football and ‘a real football match got underway’.37 37. Chandler, ‘Diary and Letters’; Klemm, ‘Letter’; MacDonald, 1914–1918; and Niemann, ‘Das Spiel endete 3:2 für Fritz’, 32. View all notes

There are no British descriptions of this game but Private Collier of the Argylls recalled ‘some of the men in the Platoon on our left had made a “ball” from paper, rags and string and went their “dinger” for about twenty minutes, until the ball fell to pieces and that was that’.

The two stories of the 133/Saxons’s officers, Klemm and Niemann, are essentially similar to Niemann’s post-war history of the battalion reporting soldiers of both sides chasing hares amongst the cabbages and then playing football. (Niemann, Das 9. Königlich Sächsische Infanterie–Regiment Nr.133; the official war diary of the 133 is missing from the Sächsisches Staatsarchiv in Dresden.) None of the British officers of the 2/Argylls mention playing football, but all agree that an ‘international’ match was discussed.

With 1,000s of young men standing around in No Man’s Land on Christmas Day unable to really converse with each other once impromptu sign languages were exhausted and trinkets exchanged, somebody would have kicked something, and somebody would have kicked it back. Then, perhaps somebody would have hurried to inflate a ball received for Christmas or carried in their packs.

It is certain that soldiers did not play a football match in No Man’s Land with stretchers for goalposts and the padre declaring Captain Blackadder offside, but with so many young men milling around, kickabout games of football with tin cans, paper wrapped with string, straw-stuffed balaclavas or perhaps with a real ball inevitably occurred, the players cheered on by their brother soldiers.

However, many, including historians, know that if any football was played, it would have been in the form of improvised kickabouts and many websites, including some pages of Football Remembers, do mention football games (plural) away from their headlines.

Iain Adams: "A Game for Christmas? The Argylls, Saxons and Football on the Western Front, December 1914", The International Journal of the History of Sport, Volume 32, 2015 - Issue 11-12, 2015 DOI

One German author, not a historian but quite thorough has sifted through quite a lot of letters and other documents relating to that fact. In Michael Jürgs: "Der kleine Frieden im Großen Krieg: Westfront 1914: Als Deutsche, Franzosen und Briten gemeinsam Weihnachten feierten", Bertelsmann: Gütersloh, 2009, he lists numerous of these occasions. One thing even this author – so eager to display the humaneness in war – soundly rejects in his conclusions is that these "matches" even produced reliable results in the form of "Argylls 2: Saxons 3", relegating this level of detail into the realm of legend.

The spontaneous truces around Christmas are certainly not a myth. The football playing occurring around these are probably not a myth.

The amount of playing that took place in every instance, the area of distribution along the front, or the amount of playing that took place overall, is very probably grossly inflated and very heavily distorted in the popular imagination and remembrance. This one is much too nice to not wanting to believe the most inflated account to be true.