somewhat impressive. for someone that size i would hope to see an extra 150 lbs. ive seen plenty of people his age half the size pull a deadlift with proper form that weighed more than that. i have always expected at least 3X bodyweight on a deadlift with experienced lifters and most people dont seem to take too long to reach that goal, about 3 months. jmo.
Generally you are correct, but it is a good lift for a 17 year old. A triple-bodyweight lift would have put him at about 150 lbs. under the world record for a raw lift, which is asking too much IMO. (As an FYI, my PR was a 465 lbs. deadlift at a bodyweight of 151.)
Now you could point out that he's using a Trap bar, with elevated handles, and that the bar is set a few inches off the ground with mats, but I'm not going to pick nits. It was a good effort with solid form, especially for a 17-year-old kid. I imagine he'll be able to add 150 lbs. to that lift easily in his first year here.
