I think it needs to be NHL to burn the ELC? Thus Wood and Santini last year in NJ.
Where as Rantanen spent a full year in the AHL last year and did not burn his ELC.
I think.
The rules aren't quite that simple but you're close.
Players who sign their ELC at age 18 or 19 are eligible for their ELC to slide 1-2 years if they don't play 10 NHL games. Rantanen (drafted from Europe and thus eligible for the AHL) had his contract slide as he signed it at age 18 and didn't play 10 NHL games. Zacha had the same thing happen as he signed his ELC at age 18 and didn't play 10 NHL games. Once you hit the 10 game mark, you burn a year off their ELC.. we did this a few years ago with Matteau which led to a whole host of problems with his waiver status.
If you don't sign at age 18 or 19, you are not eligible for the ELC to slide at all. This means that a year is burned regardless of whether the player plays a single NHL game. Wood and Santini both signed their 3-year ELC to start immediately so last year counted as their first year under contract, and would have even if they didn't play that single game. Jacobs, on the other hand, was 20 when he signed his ELC (so no slide) but his ELC didn't start until July 1st, i.e. this league year.. so this year is the first of his 3-year ELC. He wasn't eligible to play in the NHL but could just sign an ATO and play in the AHL, as he did.
So you can entice a college player to come out early by letting their ELC start immediately and burn up a year... they don't actually need to play a single game at all (so theoretically can sign their ELC on June 30th? not sure about that).
Same would apply for Kerfoot (who will be considered 23 whenever he signs his ELC this calendar year so he gets a 2-year ELC). He can sign his ELC when his season ends. If it starts immediately, he can play in the NHL or AHL (or not at all) and it will burn a year = 1 year ELC. If he signs his ELC to start next year, he can play in the AHL with an ATO = 2 year ELC. If he refuses to sign his ELC, he can sign with any team on August 15th.. but then would automatically have the full 2-year ELC.