I understand the odds of finding a Star outside of the first round. I used the word "impact" for which I would describe as a top 6 F/Top 4 D. That's what every team should be shooting for and if you draft a player with that kind of potential and he doesn't meet it, you still may fall into an NHL player. I put "star" in quotes to emphasis that Fox was a homerun and a lot different from the rest. I'm not ready to anoint him a Star after one year but he's trending in that direction. The rest are still up in the air which is why you probably have to go back further than 2015. A 2015 draftee just played his age 22 year old season. Including Phil Kemp in a potential "hit" category doesn't sit well with me. If that guy is a regular NHLer, St. Ivany is a top 4 staple.
2014:
Bjork (5th round) - Fringey NHLer
2013:
Compher (35th overall) - Possession dragging 3rd liner
Motte (4th round) - Plays in the NHL
Butcher (4th round) - Top 4 caliber
Hayden (3rd round) - Plays in the NHL
2012:
Grzelcyk (3rd round) - Solid 3 pair D
Carrick (5th round) - Fringey NHLer
2011:
Grimaldi (33rd overall) - First full NHL season at age 26. Good year though.
Boyd (6th round) - Fringey NHLer
The two best players (arguably), spent all 4 years in college and Butcher walked in UFA. Motte, Hayden are NHLers in name only. Two of the better ones out of the NTDP, ironically, are Andrew Copp and Frank Vatrano who went undrafted out of the program.
This doesn't mean that I won't want Powell or Berard on Draft day like I wanted Fensore last year. I just like to play the odds and the odds aren't exactly great.
I wouldn't have a hard or fast rule or anything, but there is a certain point with each league that historically the ROI isn't worth it. After the ~4th round for CHL players it doesn't seem worth it. That said there will probably be a CHL
defenseman or two that I'll want the Flyers to draft in the 5th or 6th round. Emphasis on defenseman since that is generally where the value is (said by a fan of the team that signed Phil Myers and Egor Zamula as UDFAs).
Also, CHL players only have a two year window to sign. Most Europeans have a 4 year window or even indefinite windows in the case of Russian players. Basic investment strategy suggests that the riskier the investment, the more time it needs to "mature" to see the best ROI. There is more runway to not only make a decision on signing a player, but to also allow that player to develop in their ideal environment.