There's established criteria on prospect eligibility. We've used it forever. Zuccarello was 23 when we signed him.
For most voters, it's not just about who has more upside. The appeal in Pionk is that as a rookie he was Hartford's best defenseman and then he was playing 22+ minutes down the stretch for the Rangers. Now, you can place him where you want, but again, for most people here it's not just about upside.
Of the guys you listed, half of them probably never play an NHL game. Again, it's not just upside. There's something to be said for a guy who has a really nice rookie year, including scoring some points in the NHL. He probably has limited upside, but he's "safe," so he made it on the list where he did.
Everyone has different motivations in voting.
I generally go for the younger guys, but I'm actually a believer in Pionk's upside and would have had him 5th on our list:
- Scored 0.5 ppg in 28 NHL games last year
- Tied Leetch's record for longest point streak by a rookie Ranger defenseman
- Scored almost a ppg in the NCAA
- Excellent skater who can use skating, puck handing, and hockey sense to create scoring chances against NHL players
- Very good one-on-one defender with high compete level
- Was matched up against NHL top lines at 22 in his first pro season
- Is just 22 with only one pro season under his belt and still has room to improve
Admittedly, a lot of the NHL observations are from a small sample size, but even if they over-represent his current ability, I think they're indicative of the upside he has. If we had any D prospects who I thought had #1 upside, I'd put them ahead of Pionk. But I don't think the upside between Hajek, Miller, Lundkvist, Rykov, and Pionk is all that different, so in that case, the guy who is closest to the NHL seems like the best prospect to me.