I believe that Russ suggested 600 because it compared to some season for Russell Wilson — the quarterback most commonly compared to Murray. Obviously, if you raise the benchmark, you're going to have a smaller group of qualifiers. Why not 1000 yards?
Russ May thrown out 600 yards, but you created a benchmark by stating:
“If Murray isn't going t rush for at least 600 yards, why did we bother drafting him? 40 yards per game isn't much, and if you're not rushing for more than that, you don't really establish the threat to run that keeps defenses honest”
So the “why bother” and “isn’t much” benchmark you set is 600.
Again I only worked with 650 because that’s the data I could find. It’s a difference of 3.1 yards per game I don’t know if that’s materially significant, but I’m inclined to think likely not.
Benchmarks are, by their nature, arbitrary. They're how you set a baseline for performance and then measure variables against the baseline. Lamar Jackson went 6-1 as a starter and rushed for almost 700 yards while making the playoffs. I'm not going to use him as a benchmark because I don't think that's a valid comparison.
Hmm, I disagree. Benchmarks, by their nature, are not typically arbitrary. At least not good benchmarks. The level of significance may vary, but benchmarks are typically set for reason. For instance, investment indices are set to determine what market rate of return you should expect without having to pay extra for active management. Within a 401(k) benchmarks may be set to determine how much nonhighly compensated employees have to defer in order to ensure highly compensateds can max out. Those aren’t arbitrary.
Your benchmark was arbitrary if we are trying to use it to determine success. But you weren’t. You were just trying to use it to state that would be easy for Murray. So essentially you were trying to set a floor expectation.
It seems to me that if your QB is going to run for over 300 yards, they're likely to be part of that dual-threat QB group that, generally, reaches 600 yards. People challenged that assumption, asserting that 600 rushing yards is an impossible goal and outside reasonable expectations.
Obviously, it's been done many, many times before, by the exact class of quarterback that we're projecting Murray into. The other class would be to look at Marcus Mariota's rookie year, where he rushed for 252 yards on just 34 attempts — which is distorted by an 87-yard run.
Very Trumpian of you. Since 1972 I showed that exactly 14 times a QB has rushed for 650+ yards in a season. Assuming an average of 30 teams per year, that means at the beginning of all of those season aggregated there were 1,410 opportunities for a QB starting the season to rush for 650 yards. It was accomplished 14 times. That’s less than 1%. Perhaps you and I just define “many, many times before” very, very differently.