I have decided to tackle the controversial subject as the debate rages in he US.
I have used the small courts and different balls for 15 years. All the schools that I ran in Mexico, as part of a national initiative to create a structured teaching system, used this method. It was not easy because the equipment was expensive, we did not have an official court size and above all, I was the only one doing this so there was no competitive structure available to support the program. However, the kids had a great time and we did develop some nice players in our program.
From a logical stand point it is difficult to argue against resizing tennis. We resize everything to make it easier for children. Why should tennis be an exception? People can argue that it is more expensive, that members do not like the extra lines on the courts, that there are not enough courts in their area, that different states have different rules, that it is difficult to retrain coaches, that many players that successfully started with the regular equipment are now in limbo, and so on, but anyone will find it hard to argue successfully against the logic of shrinking the sport.
What needs to be absolutely clear is that the main benefit of this program is the ability to teach the tactical aspect of tennis much earlier and this has two undisputed advantages: First, it makes the game much more interesting from the beginning, since kids can actually play with each other earlier, and this will definitely help improve the retention rate in the sport. Second, this initiative will change the game forever. The main reason the game has gravitated towards the baseline is the fact that kids cannot successfully use the whole court until they develop physically. If a kid is competitive he/she wants to win and that is not possible coming to the net consistently as a 9 years old. Once the kids grow, some of them develop a more aggressive attitude in terms of coming in, but it is never as natural as it could have been.
However, the true advantage of this program can only be exploited by coaches who’s philosophy and practices include a great deal of tactical training and competition among players. Coaches who are very technically oriented and who’s coaching involves a lot of feeding will not see any benefit from the change and will usually find it annoying. Technical development through repetition can be done on a regular court with regular balls.
Is the ROG method better to develop elite players? I you are talking about quantity, my answer to this would be “yes” once everything is in place. Competing under similar circumstances as adults much earlier will develop players with a more complete game. In addition, tennis is a numbers game and if the program is bringing more kids to tennis and helps retain them, then the odds of having better players automatically improve.
If the question is: Will everyone that starts with resized courts and equipment end up being a better player that those starting the traditional way. The answer is definitely "no." There are many ways to coach and extraordinary players will excel regardless of how they are coached.
Having said that, I truly believe that in 25 years we will look back and ask ourselves: how did we ever use the normal courts with traditional balls to teach younger kids? You can do so much more, much earlier with the adapted equipment. All the drills that you do with your competitive players can be started much sooner. The key is adapting your philosophy, shrinking it and starting with your tactical training much earlier - as opposed to totally changing the way you teach.