The whole thing is a vast expansion of Pascal's Triangle and works for any starting odds.
Let's start with two 'idiot' examples.
Womens' match EVENS each of two coming out.Player A wins first set and is now 3-1 on, from the line 1 2 1.
Mens' match 5 sets.EVENS each of two coming out and Player A wins first set.
You follow Pascal and go to the line 1 4 6 4 1 and from that you can deduce the odds for both players.
The problem with Pascal is that although a great maths wizard.....the Genius Kid of his day;as a tennis player he was a fish.
In other words you have to modify his figures in other ways but they are as good a starting point as any.