I do not believe we should compare the two QB's, at least not now, not at this point of Thigpen's career. Here's my reason why we can't compare them at this stage. Also will explain why KC fans are so eager to compare them.
Thigpen never played in the 2008 Patriots offense. Cassel never played in 2008 Chiefs offense. So it's really hard to compare them in that aspect. But we do know that the 2008 Patriots team was by far a better TEAM than the 2008 Chiefs. Not just by win-loss. All around better leadership, coaching and talent.
Now, to just look at Thigpen, eventhough he was drafted in 2007, 2008 was essentially like his rookie season, being his first season with KC. What he had work with in Minnesota prior year is irrelevant. If we look at Thigpen as a rookie, then, lets compare him to some rookie from 1989, who happen to be a No. 1 overall pick as well. Yeah, you guessed it, HOFamer Troy Aikman. Despite having a WR named Irvin and a RB named Emmitt, his stats were a joke (Aikman stats in 1989, 1990). And if you look at the eventual superbowl champs, their record in 1989 and 1990 weren't all impressive going 1-15 in 1989 then 7-9 in 1990, Aikman was the highest ranked QB in getting sacked.
We will not be able to compare Thigpen to Cassel because Matt played under a much better overall team that's been established. Matt was not a rookie, despite playing and starting NFL games for the 1st time in his career. Matt's been under the same system and have had 3-4 years of training camp under his belt, on top of the tutor-ledge of a HOF Brady. On the other hand, Thigpen and the entire KC team was not established to begin with. Plus, Thigpen was like 3rd of 4th in KC's QB depth chart in 2008 training camp. All from a newly installed Gailey offense. Thigpen also never had mentoring from any HOF QB. You cannot even mention Croyle and Huard in the same breath with Brady when comparing leadership of veteran QB. Thigpen's upside is huge. You can see signs of his progress from game to game last year despite taking on a make-it-up as we go offense. And also the one unmeasureable side of an NFL QB - their poise in the pocket, and confidence in the huddle (Gonzo talked about that, he said Thiggy grew as the season went on and showed signs of true leadership in the huddle). We already know what we can get of Cassel. We'd have to wait and see how Thigpen improves over the course of the next 1-2 years. Let’s give Thigpen 2 seasons under this same system, whether or not he gets to start and play in games, it makes a difference if he's got it, he will show it when he's given the opportunity, when he's been under the same system. Though under the same system, Thigpen still lacks a mentoring from a veteran QB.
I know a lot of us feel that a veteran QB is a veteran as long as that player been in the league for more than a few years or started full seasons. Not at all. If you were a rookie and you had to sit behind and learn from say Huard. Would you doubt him if he told you to look for something in the defense and then you see him doing it but throws an INT? Or you think' it'll be easier to listen and believe a veteran QB like Brady, who's won games and broken records, won superbowls. See, when Brady says to Cassel...do this, look for that, don't do this - Cassel accepts. Even when something don't makes sense for Cassel, if its Brady saying it, he is less likely to doubt. Can you imagine Huard telling Thigpen and Thiggy doubts Huard? That's what I meant by mentoring and having the leadership of a veteran QB.
I'm not saying Thigpen will not develop into a franchise type QB without a veteran QB to mentor him but if he's got what it takes, he will eventually and it will take a few years in the NFL and learning the same offensive system. That's just a normal progression that he'll have to endure to get to the next level. KC fans are so impatient, WHY? That's because none of us can remember the last time KC went through painful years to attempt and develop their own QB. If you look back to when King Carl's era begin, we've never had a young QB. It started with Jaworski, DeBerg, Dave Krieg, Montana, Bono, Grbac and then Trent Green. It's unfortunate that we invested our attempt to develop a QB in some fragile goofhead like Croyle. So while waiting on him to develop, he kept getting INJ and thus makes us feel as if we have waited long enough for a QB. Gotta give Thigpen some time, its unfair to tag on Croyle's years to Thigpen. Because if we include 2006 and 2007 when we were trying to see what Croyle can do, those years gotta be thrown out, not to be added as KC's rebuilding years. Huard was merely a stop gap while we waited on Croyle. Now that we found Thigpen, we gotta be even more patient and not rush it. So with that said, I believe Cassel to be somewhat similar to the other borrowed QBs KC brought in in the past. Situation with Matt can be linked to Grbac’s in how KC’s GM and fans view it. Elvis was an understudy behind Steve Young but when he became a FA, niners decided to let him test free agency and then King Carl signed him. Elvis looked good while subbing for Steve Young, he showed arm strength, size and can make all those NFL throws. But Elvis is not Cassel. I believe we are all clear of that. Also there’s been a statement from Rich Gannon himself. Though the situations are similar Grbac/Gannon and Cassel/Thigpen, the players are not.
And after all of that, I am in no way saying that Cassel can be compared to Grbac. It’s not even close. I was merely trying to show and link how similar the situations were in the way KC acquired Grbac and Cassel. Those two QB’s caught the attention of KC’s GM after sitting on their team’s respective benches for 2-3 years under the mentoring of a HOF QB. Now with all of that said, I am a believer that Cassel will do well. But I am also the one to say that Thigpen will also do well. So heck with it, I am tired of starving all these years for not having depth at QB position, let alone having now two potential starters. This is an awesome problem to have. Montana had Young, Young had Garcia, Favre had Brunell and Hasselbeck, Brees had Rivers, Brady had Cassel, Bledsoe had Brady, Bledsoe had Romo, Grbac had Gannon. And if you think of it, with the NFL season going to 18 games season, it’s even a greater advantage to have more than one starting QB. You never know. And here’s a little bit of stuff I came across from Keyshawn Johnson