There isn't a formula. These type problems are complicated to program.
Usually trying every combination and determing a score for each combination,
then picking the combination with the best score.

You have 6!/(4!2!) which is 15 different ways of spliting 6 people into
groups of 4. And then 3 different ways of putting 4 people into two teams of
two. Which is 45 (15 x 3) different combinations. Why don't you get 4 more
court dates and put the 45 combinations into a hat a just pick or just pick
41 times from the hat and 4 combinations won't get used. You wouldn't get a
better random selection from picking from a hat then you would by having a
worksheet do it for you. what are you calling "Evenly As Possible".

"Chris M." wrote:

I would like to create tennis schedule that schedules the players randomly.
There are a total of 6 players. Only 4 can play on any given day. We have 41
court dates throughout the year. What kind of formula can I use to make sure
the players alternate as evenly as possible?

Thanks for your help!