I've spent lots of time evaluating NFL drafts from 2000-present. For this particular exercise, I'm asking the question of: How likely are you to draft a starter? I'm using data from pro-football-reference.com. And honestly, I have it all in an excel spreadsheet but the data in the spreadsheet is a year old, because I started this project a year ago. So here's my methodology:
(1) I am only looking at drafts from 2000-2013. This is because drafts after 2013 are much more impacted by the fact that I don't have the 2022 season data in it, which does change some things, but also by the fact that the longer the career, the better chance to hit the two benchmarks I'm about to look for.
(2) Benchmark #1 is a 5-year starter. I don't want to go fewer than 5 years, because being a 5-year starter indicates to me that you aren't flukey, and that you did this for a decent length of time, with some consistency. But I didn't want to make the threshold any higher because 5 years as a starter in the NFL is really good.
(3) Benchmark #2 is a 2x Pro Bowler. I didn't want to go with All Pro because that's a super high bar to hit. And we all know that the Pro Bowl is weird, and that sometimes undeserving players make a Pro Bowl. But it does at least give us SOME indication of who is good. Generally, with enough data, being a Pro Bowler is going to give you a reasonable indication of whether a guy is good. Making it once is potentially a fluke. Making it twice shows you're pretty good. So that's my second benchmark.
You can see why I wanted to look at drafts that are 10 or more years old. Because evaluating the 2020 draft with these benchmarks is obviously stupid, as players haven't even been in the league long enough to achieve 5 years as a starter. And it's also unreasonable to look at a guy who has been in the league 7 years and hold them to a 5-year starter benchmark. So that's at least the method behind my madness here.
So with that being said, from the 2000-2013 drafts, here's the data:

So the "best" draft of the bunch, from these two benchmarks, was the 2006 draft, where 65 out of 255 players drafted (25.5%) were at least 5-year starters, and 29 players (11.4%) made at least 2 Pro Bowls. Depending on how you look at it, the "worst" draft years here were probably 2008 (17.9% 5-year starters, 6.7% 2x PB), 2009 (19.5% 5-year starters, 4.3% 2x PB), or 2013 (18.9% 5-year starters, 7.1% 2x PB).
So out of these 14 drafts, there were 3,567 players taken. 761 of them (21.3%) started at least 5 seasons, and 280 (7.8%) made at least 2 Pro Bowls.
The average team made 8 picks per year, and had 1.7 5-year starters come from that, and fewer than one player per draft (about one every two drafts, as it were) make at least 2 Pro Bowls.
So a "good" draft means that you draft two guys who end up starting for 5 years in the NFL, and a really good draft means you draft two guys who end up starting 5 years in the NFL and one of them makes 2 Pro Bowls.
(1) I am only looking at drafts from 2000-2013. This is because drafts after 2013 are much more impacted by the fact that I don't have the 2022 season data in it, which does change some things, but also by the fact that the longer the career, the better chance to hit the two benchmarks I'm about to look for.
(2) Benchmark #1 is a 5-year starter. I don't want to go fewer than 5 years, because being a 5-year starter indicates to me that you aren't flukey, and that you did this for a decent length of time, with some consistency. But I didn't want to make the threshold any higher because 5 years as a starter in the NFL is really good.
(3) Benchmark #2 is a 2x Pro Bowler. I didn't want to go with All Pro because that's a super high bar to hit. And we all know that the Pro Bowl is weird, and that sometimes undeserving players make a Pro Bowl. But it does at least give us SOME indication of who is good. Generally, with enough data, being a Pro Bowler is going to give you a reasonable indication of whether a guy is good. Making it once is potentially a fluke. Making it twice shows you're pretty good. So that's my second benchmark.
You can see why I wanted to look at drafts that are 10 or more years old. Because evaluating the 2020 draft with these benchmarks is obviously stupid, as players haven't even been in the league long enough to achieve 5 years as a starter. And it's also unreasonable to look at a guy who has been in the league 7 years and hold them to a 5-year starter benchmark. So that's at least the method behind my madness here.
So with that being said, from the 2000-2013 drafts, here's the data:

So the "best" draft of the bunch, from these two benchmarks, was the 2006 draft, where 65 out of 255 players drafted (25.5%) were at least 5-year starters, and 29 players (11.4%) made at least 2 Pro Bowls. Depending on how you look at it, the "worst" draft years here were probably 2008 (17.9% 5-year starters, 6.7% 2x PB), 2009 (19.5% 5-year starters, 4.3% 2x PB), or 2013 (18.9% 5-year starters, 7.1% 2x PB).
So out of these 14 drafts, there were 3,567 players taken. 761 of them (21.3%) started at least 5 seasons, and 280 (7.8%) made at least 2 Pro Bowls.
The average team made 8 picks per year, and had 1.7 5-year starters come from that, and fewer than one player per draft (about one every two drafts, as it were) make at least 2 Pro Bowls.
So a "good" draft means that you draft two guys who end up starting for 5 years in the NFL, and a really good draft means you draft two guys who end up starting 5 years in the NFL and one of them makes 2 Pro Bowls.