I saw both play at the USO. Donaldson is younger. He is the better ball striker. He is about 6'2" but not filled out. I would say he weighs 120. DB much taller and stronger. He has a man's body. I would say Donaldson has more upside.
Donaldson is a talented player, as well as has the finances to hire very good coaches and travel the world to encounter higher level of competition than DB. DB is certainly able and capable of matching Donaldson in the talent department, but one has to question whether not having "professional coaching" could be the difference.
It will be interesting to see how things develop in the next two years. Donaldson plays the tournaments in the right places, lie this week, for example he has to win one match against some poor soul in Venezuela (with no ranking) to qualify for the main draw of a 15,000 future. In US Or other places, to make it to the 15,000 md, one would have to win 3-4 matches in quailed and encounter possibly guys from 120-400 in the main draw. So money does buy you certain favorable conditions, although this is not to say that JD can t play. Just these particular two players could not be more different in their social status and very different from the coaching perspective.
It would be more fair to compare JD to guys like Kokkinakis or Quinzi or even Rubin or Kozlov, who do have either the money or the financial backing of the federations. They are all born in 1996 and yet Quinzi will be around 700 ATP when rankings come out, Kokkinakis around there as well. And both Rubin and Kozlov already have Atpbpoints and are way ahead of JD on the ITF scale.
