Its not a debate between Ray and Estevez. Ray is a mere months older than Estevez, but has already had a full season of quality performance at Hagerstown. He's a step above Estevez on the ladder, is left handed, and has better stuff. It's not a debate.
How do you know he has better stuff?
Scouts seem to hate Ray, for what it's worth.
9) Robbie Ray, LHP, Grade B-: Borderline C+: Limited pitch counts in Low-A, but strong K/IP ratio. Reports on stuff and projectability are mixed, but he did well for a 19-year-old in full-season ball.http://www.minorleagueball.com/2011/12/20/2650433/washington-nationals-top-20-prospects-for-2012
Ray was said to have an advanced feel for his secondary pitches that most 19 year olds don't have and that low A ball players are not ready for. It'll be interesting to see how his stuff plays as he moves up the ladder.
I get the argument about the age of guys like Karns and Turnbull, etc but age isn't the most important thing. Stuff is. Shairon Martis always performed well in the minors despite being much younger than his competition, but his stuff wasn't big time. He made it to the bigs at a young age, got tossed around, and hasn't made it back. Not saying Estevez is on the same track. Just saying, numbers at a young age without the standout stuff doesn't make you a great prospect.
Whether or not Karns and Smoker are relievers isn't a great argument either IMO. If you have a power arm and can make an impact, even as a reliever, Ill take that over a marginal starter. At this point, that's all Estevez is. He absolutely has potential and a projectable frame, so he's not a finished product. But he does have a long way to go to be a legitimate prospect IMO.
What does "legitimate prospect" mean? If you look at Sickels list Turnbull, Smoker, Hill, etc... are all on the "OTHERS TO WATCH" list just like Estevez can't see how any of those guys are any more legitimate than Estevez. Did you read the Byron Kerr article I posted earlier Doug Harris seems to think the kid has good stuff. We'll agree to disagree on the whole reliever prospects v. starter prospects argument. I don't think Estevez is a "great prospect" but I do think post the Gio trade he has a claim to Top 5 pitching prospects in the Nats organization and could become a mid-rotation starter if things work out.