Here are some "popularity" numbers, for those interested. This comes from the reputable (and proven) gamestats site. PS and Xbox numbers could be off by as much as 10%. Steam just gives a rough range. NSW has nothing.
Tennis World Tour has 450k across PS, 92K on Xbox and a vague estimate of 20k on Steam.........so it's had around 560,000 unique gaming accounts that have played the game.
AO Tennis International has 160k on PS, 71K on Xbox and again, an estimate of 20k on Steam.......251,000 players.
AO Tennis 2 has 59k on PS, 12K on Xbox and the generic 20k on Steam.........91,000 players BUT this has only been out for 3 months, so thats quite strong, all things considered.
Keep in mind that these are NOT in any way Sales totals. Many people could buy the game and never log into their accounts when they play- and this doesn't include the Nintendo Switch at all. The only game we have any sort of true numbers for is Tennis World Tour, which we know shipped over 500k and SOLD over 300k copies.
This is purely just to get an idea of how popular a game is, what it's daily player count looks like and how active the community is.
AGAIN, these numbers are not about much these games have sold. This is just information that is readily available on the internet for EVERY video game.