10 tennis players, 2 courts, 26 rounds

[Ian Wakeling]

With 9 players things are easier, since the standard Whist schedule with 9 rounds should work for you (this gives all partners once and all opponents twice).   I have put three copies of this below, just leave out the last round if you need only 26 rounds.

[(B A):(E G)] [(C I):(F H)]
[(C H):(D B)] [(F G):(E I)]
[(E F):(H A)] [(I D):(G B)]
[(F I):(A D)] [(C G):(E H)]
[(G I):(A C)] [(B E):(D F)]
[(D E):(I H)] [(A F):(B C)]
[(G D):(F C)] [(I A):(H B)]
[(H G):(B F)] [(D C):(A E)]
[(C E):(I B)] [(H D):(G A)]

[(B H):(C D)] [(F I):(E A)]
[(E I):(D G)] [(F H):(B A)]
[(A D):(B E)] [(H C):(I G)]
[(G C):(F A)] [(E H):(B I)]
[(I A):(G B)] [(C F):(D E)]
[(I C):(F B)] [(H D):(A G)]
[(H I):(D F)] [(G E):(C B)]
[(E F):(H G)] [(A C):(I D)]
[(A H):(C E)] [(D B):(G F)]

[(D B):(I G)] [(A F):(C E)]
[(A E):(G H)] [(C B):(D F)]
[(B H):(A C)] [(E G):(F I)]
[(D A):(F G)] [(E H):(B I)]
[(E I):(C D)] [(F H):(B G)]
[(C F):(H I)] [(D E):(A B)]
[(F B):(I A)] [(G D):(H C)]
[(B E):(G C)] [(I D):(H A)]
[(E F):(H D)] [(G A):(I C)]

[Offtopic]

I have now removed "player C" and instead of this games I replaced each "C" with A-J (excl. C). I only will play with the order of rounds (player H playes round 2 to 5 in a row)

[Offtopic]

I used now your generated data to generate several different schedules - thank you very much!

I only have troubles to avoid too big gabs for at least two players:
I have generated some formulas to check the distribution of each player on the schedule

Here you can see highlighted Player F (yellow) and H (orange):
H has a gab between round 1 and 7
F between 8  and 13

Is it possible to avoid such big gaps?

[Ian Wakeling]

What if you reformat my 1st schedule above like this:

[(B A):(E G)]
[(C I):(F H)]
[(C H):(D B)]
[(F G):(E I)]
[(E F):(H A)]
[(I D):(G B)]
etc....

[Offtopic]

With above rule one player has 2 times a gab of 4, but it's okay.
I don't want to invest more into this schedule

Thank you very much - again!