So, the offhand games you are discussing were played before and after their first round encounter in the tournament, and hence I wouldn't call it a match. Anderssen reports that he had challenged Löwenthal for a match of 11 games and a stake of 5 pounds. I think you see the difference. Moreover, I would not even call them 'a series of games', because I assume that there was more than one such series. Many offhand games by Anderssen and Kieseritzky are reportet with several other opponents, as well.

The exact number of these offhand games is unknown, which supports their occasional character, as well as the large number of their mutual and other encounters shows that they were played more rapidly than the tournament games.

The stroke that has paralyzed his left side seems paradoxically to have stimulated his mind in certain ways and at certain times. Usually listless, he will be clothed and unclothed, bathed and examined, fed and assisted with his toilet. His stool is like rock or shrapnel. When animated he will write feverishly in his notebook and is heard muttering about ‘the small and humble star rising in the west’. It is as though he is prophesying the fate of mankind. His sole consolation is his chess set. He had been slumped over it in his lodgings when found by the police who had been called by his landlord. My assistant Foch felt that this one familiar object might be helpful in his stabilisation and therapeutic recovery. For this I hold out little hope, despite his relatively young age of 47. Recovery is as much a matter of volition as it is a neurological healing and functionality.

The sad truth is that friendless and penniless M. K- has little for which to live. His debts are considerable as letters found in his lodgings reveal. ‘La Régence’, the magazine which he had published having failed, his sole source of income was the daily games of chess he would play for a fee with all comers. Debtors have already sold off those volumes and other belongings found in his apartment. Were it not for the Sisters who daily tend and feed him, he would simply starve and rot in his own filth. Faith of any sort, Catholic or Protestant, does not seem to have featured in his life. The most we are doing for this poor unfortunate is keeping him comfortable until death finally embraces him. That, in my view, will come soon…"

http://www.chesscentral.com/a-famou...

In this book:

https://www.redhotpawn.com/imgu/blo...

we see this game reproduced thus.

https://www.redhotpawn.com/imgu/blo...

<M Kieseritzkij died some time back; melancholy to say, in the Hotel Dieu, the authorities of which applied to the Paris Chess players to bury him by a small subscription, but this was so ill-responded to that poor Kieseritzkij was buried the burial of a pauper. Truth is, the Paris players are broken up, the club all but gone, and the band who should keep alive the sacred fire without head or permanent locale. The Cafe de la Regence is to come down, its site being required for building improvements.>