Jumat, 27 Maret 2009

Texas Tech - First-Year QB Comparisons

From Double-T Nation:

For the first time in two seasons, Texas Tech has a brand quarterback and although we're accustomed and grateful for what Graham Harrell did, it's time to look a bit forward and wonder what Taylor Potts might bring to the Red Raiders as a first year starter under Mike Leach's system.

Going into Graham's second year, I asked how much he could improve from one year to the other, but this time I thought that it might be a good idea to take a look at Symons, Cumbie, Hodges and Harrell's first (and sometimes only) year. The nice part about this is that it's a nice mix of players. It's not just one type of quarterback, which means that perhaps there's actually something to gain from looking at what we can expect.

. . .

Playing It Safe

What's the one thing that jumps out at Harrell's 2006 season? For me it's the fact that he had over 50 attempts for every interception. Contrast that with the touchdowns per attempt? Now, contrast that with Symons and what does that tell you? For me, it tells me that Symons was a guy that was going to take chances, while in Harrell's first year, he was dead set on playing it safe, evidenced by the lowest yards per attempt of any of the four, although he only beat out Cumbie in that category by one-one-hundredth of a point. There's got to be some middle ground here, and taking a look at Cumbie's 2004 season, his touchdown to attempt ration is far and away better than his partners in crime. Statistically, he's really not much better than his fellow quarterbacks and lost in all of this, sometimes is that Cumbie was just damned good at putting the ball in the endzone.

My Favorite QB Stat

I've probably beaten everyone over the head about yards per attempt and it's a really bad habit, but if you'll indulge me here, I'll try to make this quick. In the Air Raid offense, there may not be a more telling statistic about the success of a quarterback than yards per attempt. Every offense is better when the team is moving the ball vertically, rather than horizontally. That's probably one of the real misconceptions about Leach's offense, is that the intent may be to make it a dink-and-dump offense, but I think this is more than likely a product of the quarterback rather than the offense itself. Exhibits "A" and "B" are Symons and Hodges. Granted, the Air Raid is not as vertical as many other offenses, but taking last year as an example, Texas Tech ranked 20th in the nation at 8.11 yards per attempt. The offense bogs and becomes not as effective if the pass is going sideline to sideline.


While I completely agree that yards per pass attempt is the most valuable passing statistic, I also think it can be adjusted slightly to better capture the issue Seth is looking at here. Specifically, you can factor in interceptions using a simple rule of thumb. This is relevant here particularly for the raw numbers between Graham Harrell's first season, in 2006, and B.J. Symons's first and only season, in 2003.

- With raw numbers, Symons threw for 5336 yards on 666 attempts, for a yards per attempt of 8.01. He also threw 21 interceptions.

- For Harrell in 2006, he threw for 4555 yards on 617 attempts, along with only 11 interceptions.

What the stat guys are doing now is subtracting 45 yards for every INT thrown: they've crunched the numbers, and this is about what it takes away from you in terms of field position, scoring probability, etc.

If you did that for Harrell in 2006 (multiplying 11 times 45 yards and subtracting that from his raw passing yards) you get him 4060 adjusted total yards. Compare that with Symons' 21 INTs, which brings his total down to 4391. This makes their adjusted yards per attempt stats now 6.58 (Harrell) and 6.59 (Symons) -- nearly the same, though by different roads. Interesting, no?

The other X factor is QB sacks/runs. College stats make this hard of course: in the NFL, sacks are counted against passing yards and thus factored into yards per attempt. For Texas Tech QBs I think the safest thing is to just count the rushing attempts and yards all as part of the adjusted yards per attempt. (If this was Oregon or Tebow at Florida it'd be very difficult to do this without completely going back to the raw data and recreating the "sacks" and "yards lost by sack" statistics.)

Harrell's rushing stats in 2006 were 32 rushing attempts for -66 yards. Throwing that with the above adjusted numbers makes his new adjusted-adjusted total yards 3994, his total adjusted-adjusted attempts 649, and his adjusted-adjusted yards per pass attempt 6.15.

For Symons, in 2003 he rushed 74 times for 140 yards. Adding this to his passing attempts/yards we get 740 attempts and 4531 adjusted-adjusted yards. (I know that this number, unlike Harrell's, is actually positive, but I think it defensible to add it all back in because few Tech QB runs -- other than sneaks -- are called run plays.) So the adjusted yards per attempt is 6.12.

So Harrell actually beats out Symons in adjusted-adjusted yards per attempt, 6.15 to 6.12, though that's basically too close to make a call. I think it reinforces Seth's point that Leach has gotten it done with QBs of vastly different styles, especially considering these two guys were (probably) the best of that run by Leach where each first-year QB excelled that Harrell broke by starting more than one season.

In any event, the real point of this is to show how you might compare apples to oranges for any system or QB, with a guy like Symons who was acting as more of a gunslinger and Harrell who -- within the confines of Leach's wide-open offense -- was operating slightly more conservatively.

(I don't have exact cites but credit must be due to Advanced NFL Stats and the Pro Football Reference Blog, both of whom have undertaken similar analyses.)