Concerns about players getting taller have been around for quite a long time: e.g. Rohit Brijnath's article in 2000 (https://www.rediff.com/sports/2000/dec/01rohit.htm). We then lived through the greatest era of men's tennis where all the main protagonists were 6ft or taller (Big Three + Murray + Stan + Delpo).
That said, I think it might be the case that if *all* the top men end up well over 6ft the variety in the men's game will become increasingly limited compared to the women's game (which seems to continue to accommodate players of all heights at the top judging by e.g. the winners of the last 20 "Big Titles"). One reason I think this outcome is unlikely in the long term is that the comparative advantage of being the guy with a superhuman return and ability to get everything back on both wings will be extremely high if all the comeptition is playing a "first serve and forehand" game.
I think after the big 3 retire the top ten stands a good chance to be made up of mostly 6ft4 and up. And RE variety, shots like the slice among those tall elite players is already quite uncommon with the exception of Berrettini. I also think your last sentence is already true, and one of the reasons Djokovic & Nadal have dominated tennis over the last decade is that a return of serve edge is a more rare competitive advantage in elite men's tennis than a big serving edge.
Concerns about players getting taller have been around for quite a long time: e.g. Rohit Brijnath's article in 2000 (https://www.rediff.com/sports/2000/dec/01rohit.htm). We then lived through the greatest era of men's tennis where all the main protagonists were 6ft or taller (Big Three + Murray + Stan + Delpo).
That said, I think it might be the case that if *all* the top men end up well over 6ft the variety in the men's game will become increasingly limited compared to the women's game (which seems to continue to accommodate players of all heights at the top judging by e.g. the winners of the last 20 "Big Titles"). One reason I think this outcome is unlikely in the long term is that the comparative advantage of being the guy with a superhuman return and ability to get everything back on both wings will be extremely high if all the comeptition is playing a "first serve and forehand" game.
I think after the big 3 retire the top ten stands a good chance to be made up of mostly 6ft4 and up. And RE variety, shots like the slice among those tall elite players is already quite uncommon with the exception of Berrettini. I also think your last sentence is already true, and one of the reasons Djokovic & Nadal have dominated tennis over the last decade is that a return of serve edge is a more rare competitive advantage in elite men's tennis than a big serving edge.
What is your definition of the trend? Is this a least square regression line?