In one week, the Detroit Lions will likely draft quarterback Matthew Stafford as the No. 1 overall pick.
USC quarterback Mark Sanchez and Kansas State's Josh Freeman are both candidates to be drafted in the top 15 picks.
It's no sure thing, however, that any of them will pan out as analysts believe. For every Peyton Manning, there's a Tim Couch or Ryan Leaf, a highly-touted prospect who is called a bust in three years.
In this series, I'll be looking at the 20 drafts from 1985 to 2004 to see how a player's draft round correlates (if at all) to their expected career performance. In the first installment, I'll be examining quarterbacks—is a quarterback selected in the first round any better than one selected two or three rounds later?
All data comes from Pro-Football-Reference.com. For players that never played a game but were still drafted, I did not just throw them out of the sample; instead, I took the stats of Mike McMahon—who had a career passer rating of 55 (below replacement level) with just over 500 pass attempts—for their hypothetical career lines.
The graph below shows the likelihood of a quarterback being selected to one or more, two or more, or three or more Pro Bowls in his career. In the first instance, there is almost a perfect linear relationship after the first four rounds.
There were only seven quarterbacks drafted after the first round who made three or more Pro Bowls; 167 were drafted. As you can tell, there weren't enough QBs to make three Pro Bowls to be statistically significant.
The graph below shows the average passer rating (weighted by attempts, of course) of a quarterback selected in each round. Notice that there's a steady decrease after almost every round.
The rating for the last round was 61.8, so I didn't show it in order to allow a better close-up of the first six rounds. The graph shows the difference between first and second round quarterbacks is minimal, but after that the production is much worse.
The next (and my favorite) graph shows the probability of a quarterback having either a career passer rating above 80 or below 75; use this as a bust-or-not detector. Only quarterbacks with more than 500 career attempts were included, but the percentages were found using the total number of QBs in the denominator (as opposed to just those with 500 attempts).
The blue line, which shows players with a rating over 80, is almost identical to the graph above (save for the different values in the second round). The red line, which essentially shows the percentage of busts picked, has no pattern whatsoever—in fact, quarterbacks picked in the first and second rounds have the greatest chance of having a passer rating under 75, while those in the fourth round have never done so (with a significant 34 QBs picked in the fourth round).
Pay attention to whether the blue line is above the red; if so, that means there's a better chance of a quarterback having a solid career than that same QB having a sub-par career. The first, fourth, and sixth rounds—in that order—had the biggest positive difference; all other rounds either had the same number or a one player difference of good and bad picks.
How does the average quarterback fare in a full season's worth of play? The following table shows the stats (per 550 attempts) of the average QB in each round, as well as the overall average quarterback.
Yardage and completion wise, there's an obvious trend—the stat in question drops steadily through the first five rounds, increases in the sixth, then drops off in the seventh. As for touchdowns and interceptions, there's nothing to take away, as both are wildly inconsistent.
The final graph below shows the years as the primary starter (as denoted by P-F-R) for a quarterback drafted in each round.
This graph backs up what all the others have before: There's a near-continuous downward trend from the first through the fourth rounds, before a small increase to the fifth and a larger one to the sixth, and then a big drop to the seventh. If you go back to the very first graph, the percentage of quarterbacks with one or more Pro Bowl appearances looks virtually the same as this graph.
What Does All of This Mean?
1. Despite the high number of infamous busts, quarterbacks selected in the first round have the best chance of having a passer rating over 80 and the biggest difference in successful/non-successful picks.
2. Second-rounders have the second-highest passer rating on average, but they also have the most risk, with more quarterbacks with a passer rating less than 75 than quarterbacks with a passer rating over 80.
3. Sixth-round quarterbacks perform almost as well as third-rounders in their career. They have a better chance of making the Pro Bowl, less risk, and an equal chance of panning out than third-rounders. The QBs selected in the sixth round, though, had a lower average passer rating by one point and just over one-third of a year less as the starter than third-rounders.