Last year I did an analysis of 1st round WRs to see what we could learn. The main takeaway was that WRs either show us their talent right out of the gate or they never show it.

So I decided to take a look at 1st round offensive linemen to see if there are any trends, how they help (or hinder) their teams in year one, or any other interesting statistical quirks that might appear.
This study is a little different from last year, it has to be, because we don't have reception percentage or touchdowns to compare individuals, so how do we compare them?
The only stats site that comprehensively grades offensive linemen is PFF. Now before you start throwing things at your computer, TV or the cat, I am not a complete worshiper of PFF or analytics in general, but it does have it's place and every team uses analytics to some degree, and PFF at least compares each player using the same metrics, so that's all we got.

How to interpret the grades:
100-90: Elite
89-85: Pro Bowl Caliber
84-70: Starter Quality
69-60: Backup Caliber
59-0: Replaceable


2011:
Pouncey and Castonzo earnt starter quality grades, although Castonzo only played 154 snaps. Four players earnt backup grades, but with Carimi playing less than 100 snaps it's not worth much. The other two graded out as replaceable though Sherod has a small sample size.
Overall if we use a 65.0 grade as a cutoff point, Pouncey and Smith were the only two players to offer something good to their team as a rookie while Smith and Castonzo were above average.
So 4 out of 8 players contributed. (50%)

2012:
This was a pretty good crop of 1st round rookies. Three above 75 although Reiff only playing 326 snaps is a limited sample size by PFF standards. DeCastro only played 136 snaps and graded poorly.
3 out of 4 for this class. (75%)

2013:
Overall a good class with one player grading in the 80s and four in the 70s. Fluker graded out just below 70 and certainly had a decent rookie year while Cooper was lost in the pre season to a broken leg, so we won't count him.
6 out of 8. (75%)

2014:
Martin had an outstanding rookie year and Lewan was also very solid. The others were below average and missed our cutoff point.
2 out of 5. (40%)

2015:
Only one player (Scherff) graded above 70. Tomlinson was solid while Ogbuehi's sample size of 66 snaps won't count for much in this analysis.
2 out of 6 (33%)

2016:
This was a good class. Decker and Conklin lead the group both scoring in the 80s. Stanley and Kelly hit the 70s while Tunsil was decent although his 64.3 just misses the cutoff point. It seems like an injustice to only have a 57% grade, if you include Tunsil it jumps to 71%, but a cutoff is a cutoff and I don't want to mess up the final analysis.
4 out of 7. (57%)

2017:
A very small sample size with only two linemen taken in the first round. They were both significant contributors though, so a perfect result.
2 out of 2. (100%)

2018:
This was expected to be a great OL class, with Nelson and McGlinchey highly thought of in the pre draft process. While things don't always work out with player projections the two Notre Dame alums lived up to expectations. Ragnow was solid enough while Wynn tore an ACL and missed the season so he won't count here.
Billy Price and Kolton Miller were real disappointments.
3 out of 5. (60%)

2019:
This was a very underwhelming class, with only Lindstrom hitting a serviceable grade. Williams suffered a shoulder injury in OTAs that required surgery and missed the season.
1 out of 5. (20%)

2020:
Last years class was a very mixed bag. Both Wirfs and Becton were really good, Thomas and Wills were underwhelming as top 10 picks, Jackson and Ruiz graded below replacement level, and Wilson decided to go off on some tangent to La La land.
2 out of 7. (29%)

So what do we learn from all of this?
It's already well established that drafting is difficult. There is no sure fire guaranteed can't miss prospect. Drafting a top 10 prospect isn't a sure fire thing, as 7 out of 17 guys in this study were underwhelming.

Overall, if we take an average from the last 10 years, 41.3% of our prospects graded out above 70 which is starter level by PFF metrics. If we lower the threshold to use 65 as a pass mark, then the number increases to 55.3% which is serviceable by rookie standards.

So in summary, you have a slightly above 4/10 chance of landing a player who will play at about starter level in his rookie year, and a 50/50 chance that your guy will be average. It should also be remembered that rookie performance is not an indicator of future level of play. Some guys play better with more experience, some fall off a cliff, and others show marginal improvement form below average to average, while some are elite out of the box and maintain that for an entire career.