When the Rockies took Lambert, an 18 year-old righty out of San Dimas High School (San Dimas high school football rules!) with the 44th overall pick in the 2015 draft, he was the fourth consecutive high schooler they'd taken to start the draft class (it would soon be five with high school righty Javier Medina in the third round). This pick strategy was seen as an investment in high upside (and far away) talent, and it represented a little bit of a different tack than had been taken previously by Bill Schmidt and the Rockies.
As for the prospect himself, Lambert's profile is summed up pretty well by Kiley McDaniel of Fangraphs before the draft (he ranked Lambert 59th):
Lambert isn't the sexiest prep arm, as he doesn't throw particularly hard or have lots of physical projection, but he has a bit of both and, more importantly, advanced feel for a three pitch mix to go with a clean arm action.
McDaniel rated Lambert's the three pitches (fastball, changeup, and curveball) and command as having a present value of 45-50 with a future value of 50-55 on the 20-80 scouting scale. It should be noted that McDaniel was on the low end of draft evaluators for Lambert. Others rated him around the 48th best prospect in the draft.
In terms of his professional career, Lambert signed for $1.495 million, about $100k over slot, and was assigned to rookie ball in Grand Junction. In eight games pitched with the GJ Rockies (all on an innings/pitch limit), Lambert threw 31 ⅓ innings with a 3.45 ERA, 1.28 WHIP, 7.5 K/9, and 3.2 BB/9. Not outstanding numbers, but considering that Lambert was throwing to hitters that were on average 3.3 years older, that's plenty good. I think Lambert looked even better to PuRPs voters given the major struggles encountered by first round pick Mike Nikorak (more on him later in the list) against the same competition.
Recently, MLB.com ranked Lambert 16th in the system:
Lambert has a combination of now stuff and projection and at 6-foot-2, 185 pounds, Lambert has a good body and frame, with room to add some strength. He's already shown the ability to touch 93-94 mph and sit around 92 mph with his fastball. He combines it with a solid breaking ball and a good feel for the changeup. He throws strikes and durability is not a concern.
I ranked Lambert 20th on my personal list due mostly to the draft pedigree, the scouting reports, and because the Rockies treated him very carefully in his first professional season. I look forward to seeing Lambert with his training wheels off (or at least with fewer restrictions) next year, presumably in Low-A Asheville.
For additional videos of Lambert and his arm action, check out Cameron Kmen's article on Lambert for ChicagoNow.