There's no logic in this argument. Even if Brissett starts and does well, it'll be on a dramatically reduced playbook that's pretty much designed to get the most you can out of whatever he's been able to pick up over a week or two.
Jimmy G has spent 2 years learning this offense. Brissett has spent a couple months. I like Brissett, but even if he plays two weeks and plays well, there's simply no way he's anywhere near as far along as Garoppolo is. Once healthy, Garoppolo will be the primary backup no matter how well Brissett does, because McDaniels likes having a full playbook to work with.
Between a thread like this and the various "Garoppolo is the future!" posts, I'm kinda coming to terms with the fact that a lot of people have trouble understanding the impact of experience, game tape, and the weekly back-and-forth between offensive and defensive coaches in the NFL.
Tier 0: You cannot play NFL QB, because your deficiencies are so glaring that DCs don't even need game tape and a customized gameplan to exploit them - examples: Brandon Weeden, Johnny Manziel. This is basically the catch-all for any QB who doesn't belong in the NFL.
Tier 1: You're capable of succeeding in the NFL for a game at a time - example: Matt Flynn. Any QB who was able to do well for a game or so before there was any game tape on him. May or may not be able to handle customized game plans once DCs start to look at their tape, but for the moment they're able to put up a credible performance.
Tier 2: You're capable of playing well in the NFL for weeks at a time using a dramatically simplified playbook - example: Tyrod Taylor. These QBs flash a bunch of talent, but since the scheme is simple opposing defensive coordinators pick up on it fairly quickly. Since the QB doesn't have a full grasp of the playbook, it's very difficult to counter defensive adjustments, and you typically see a dramatic downward correction in the QB's performance within a matter of weeks.
Tier 3: You're capable of playing well in the NFL for a season at a time using a relatively full playbook, but relying on a couple of signature skills/tendencies/matchups - examples: RG3, Kaepernick. These QBs succeed for longer stretches, like 6+ weeks up to a full season or two. But eventually, their tendencies get exposed and defenses gameplan to take away these crutches and force them to adapt. Only those who can adapt and maintain their level of success make it to...
Tier 4: You're still able to succeed even after NFL coaching has adjusted to you and drawn up gameplans specifically to stop you based on a wealth of game tape exposing every flaw in your game - examples: Brady, Rodgers, Newton, etc. This is the final tier. Every QB has flaws in their game--for Brady it's that he doesn't escape the pocket very well and doesn't throw great on the run--but the best QBs have found a way to minimize those flaws, and are able to attack and beat any defense, even those that are tailored to take advantage of their specific flaws. It won't work every time, but they can do it.
Last week, Brissett proved that he's definitely above tier zero. Based on how the Pats called the game after he came in, I think we can safely put him on tier 1, with the potential to get to tiers 2-3 with more time in the system.
Last week, Garoppolo proved that he's tier 2 at a minimum, and maybe even tier 3. Tier 4's theoretically in play. Most QBs never get to tier 4 though, so for anyone who isn't already there it shouldn't be assumed that they'll get there.
There's no doubt in my mind that the Pats are willing to keep a roster spot open for Jimmy purely by virtue of tier 2-3 QBs being far more valuable as backups than tier 1 guys. Conversely, when comparing Brady vs. Jimmy, the point I keep coming back to is that Brady is a proven tier 4 guy, while for all we know Jimmy might be tier 2. I'll take 3 years of tier 4 over any number of years of tier 2, and even a lot of years of tier 3, because tier 2-3 is replaceable. That's the level that great coaches like Belichick/McDaniels should be able to coach a talented, sufficiently hard-working prospect up to. Tier 4 is the rare asset that you simply can't let go if you have it. It's why the Falcons, for example, will turn over their entire organization, top to bottom, before they move on from Matt Ryan. Because he's shown compelling evidence that he might be a tier 4 guy stuck in a crap situation.
