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QB Brock Purdy Thread

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QB Brock Purdy Thread

Oct 3, 2023 at 7:37 PM
Originally posted by Memphis9er:
Originally posted by 5_Golden_Rings:
Originally posted by 49erKing:
Originally posted by 5_Golden_Rings:
Originally posted by Giedi:
Originally posted by brodiebluebanaszak:
Originally posted by Giedi:
Originally posted by tankle104:

Arm is definitely stronger than Montana's.

No not really. They both throw extremely catchable balls on all their different types of throws though. Both elite there.

Disagree, I remember Montana's long balls had more arch to them. Early in Montana's career (Before Rice) he had long ball issues. Which are not a big deal during the early years as he had Wendell Tyler. That Aiyuk 40+ yard throw was a flatter trajectory than Montana's usual deep throws, as I recall it.
Having a lower trajectory on deep balls all the time means your arm isn't as strong, because you have to cut out the wasted motion. You think Russell Wilson has a weak arm? His deep balls are more tear drop than anyone's I've ever seen.

The second the ball leaves your hand, the only forces working on it are gravity and friction. A high arching ball travels a further net distance than a flattened one. It takes more arm to throw more distance. QBs who depend on a flat arc for deep balls probably do not have as strong an arm as those who don't.

HOWEVER, it could also merely be a preference. The QB maybe doesn't anticipate as much as the tear drop guy and has to sling it to get it there in time, or perhaps they're paranoid about the ball taking a long time to get there.

.
.
.
EDIT: before I get tarred and feathered, I'm not talking about Brock. His arm is plenty strong enough to hit every throw you need to wear a gold jacket. I'm just talking theoretically. If you HAVE to have a low trajectory to throw deep, your arm isn't as strong as someone who can easily do either.

Any science behind this? I think if someone wants to throw deep, if they have the time, and it makes sense, they "naturally" conform to throwing with a higher arc/higher trajectory. I mean that's how I feel when I play catch with the guys. If you're trying to laser it while going deep I think that actually means you have a stronger arm than most.

Yeah. Pythagoras (Extended to curves; the same principle applies, you just add up the infinitesimal distances via a line integral, but it's essentially the same thing. In Euclidean geometry, a straight line is the shortest path between two points.). A high arcing ball travels more distance. As the ball is not getting any additional force as it leaves (basic physics), what you put into it upon release is all it has. So throwing with a high arc doesn't give you some boost. That's not how physics work. Draw a free body diagram. Only gravity and friction are of any consequence once it's released.

So, the high arcing ball is thrown further in actual distance traveled than the low arcing one.

Which means, if you MUST throw with a low arc to get it there, your arm is weaker. (By arm strength I mean how far you can throw the ball, but I see no reason why velocity and distance would be different as a measure of arm strength unless the QB has mechanical problems which make one of either his distance or velocity throws more inefficient.)

.
.

EDIT: Just to be clear, however, I do believe that the most likely reason most of the time for why some QBs throw with a low arc and some don't is that the low arc guys either have poorer deep anticipation or don't trust their accuracy and timing as much, or fear that a super fast safety might catch up and make a play. In other words, I think a lot of low-arc deep ball guys COULD throw tear drops but choose not to.

Kaepernick used to throw frozen ropes, I don't think he could put air under it. It takes more strength to throw those low angle passes because you have to put more mustard on it to get the ball to go where you want it. The downside is those balls are much harder to catch. Putting air under it means you don't have to throw it as hard to get it to the target, and the balls are much easier to catch. Josh Allen is probably the best pure arm talent that can do either as needed.

If you follow the conversation, it depends on if you're throwing with an angle greater than or less than 45. Which one takes more arm strength swaps at that critical point.
Oct 3, 2023 at 7:39 PM
Originally posted by Chance:
True, but at the end of the day, there's less gap to bridge when you're arguing whether a particular throw was good or bad. Not whether a player should be kicked to the curb or given the starting job. These arguments in this thread have been small because we're only arguing the degrees at how well Brock is playing. That first bad game or stretch of games, and I guarantee people will come out of the woodwork and real s**t-slinging will begin.

Oh I'm sure you're right about that. That's going to happen even if he plays great all year and we don't win the SB, lol.
Oct 3, 2023 at 7:39 PM
Originally posted by AB81Rules:
Originally posted by blizzuntz:

caleb wants to be our back up

I wonder how true this is, I'm warry of these types of accounts, unless I missed something where Caleb said this, or hearsay.

I had thought if he declares for the draft, he becomes ineligible to play college ball, and if he declares fro the draft and turns down the team that drafts him, he has to sit out of the NFL for an entire year. I guess he could still make endorsements with USC, but he won't be playing. Unless the rules have changed.
Oct 3, 2023 at 7:40 PM
Originally posted by Memphis9er:
Originally posted by 5_Golden_Rings:
Originally posted by Chance:
Originally posted by 5_Golden_Rings:
Originally posted by 49erKing:
Originally posted by 5_Golden_Rings:
Originally posted by Giedi:
Originally posted by brodiebluebanaszak:
Originally posted by Giedi:
Originally posted by tankle104:

Arm is definitely stronger than Montana's.

No not really. They both throw extremely catchable balls on all their different types of throws though. Both elite there.

Disagree, I remember Montana's long balls had more arch to them. Early in Montana's career (Before Rice) he had long ball issues. Which are not a big deal during the early years as he had Wendell Tyler. That Aiyuk 40+ yard throw was a flatter trajectory than Montana's usual deep throws, as I recall it.
Having a lower trajectory on deep balls all the time means your arm isn't as strong, because you have to cut out the wasted motion. You think Russell Wilson has a weak arm? His deep balls are more tear drop than anyone's I've ever seen.

The second the ball leaves your hand, the only forces working on it are gravity and friction. A high arching ball travels a further net distance than a flattened one. It takes more arm to throw more distance. QBs who depend on a flat arc for deep balls probably do not have as strong an arm as those who don't.

HOWEVER, it could also merely be a preference. The QB maybe doesn't anticipate as much as the tear drop guy and has to sling it to get it there in time, or perhaps they're paranoid about the ball taking a long time to get there.

.
.
.
EDIT: before I get tarred and feathered, I'm not talking about Brock. His arm is plenty strong enough to hit every throw you need to wear a gold jacket. I'm just talking theoretically. If you HAVE to have a low trajectory to throw deep, your arm isn't as strong as someone who can easily do either.

Any science behind this? I think if someone wants to throw deep, if they have the time, and it makes sense, they "naturally" conform to throwing with a higher arc/higher trajectory. I mean that's how I feel when I play catch with the guys. If you're trying to laser it while going deep I think that actually means you have a stronger arm than most.

Yeah. Pythagoras (Extended to curves; the same principle applies, you just add up the infinitesimal distances via a line integral, but it's essentially the same thing. In Euclidean geometry, a straight line is the shortest path between two points.). A high arcing ball travels more distance. As the ball is not getting any additional force as it leaves (basic physics), what you put into it upon release is all it has. So throwing with a high arc doesn't give you some boost. That's not how physics work. Draw a free body diagram. Only gravity and friction are of any consequence once it's released.

So, the high arcing ball is thrown further in actual distance traveled than the low arcing one.

Which means, if you MUST throw with a low arc to get it there, your arm is weaker. (By arm strength I mean how far you can throw the ball, but I see no reason why velocity and distance would be different as a measure of arm strength unless the QB has mechanical problems which make one of either his distance or velocity throws more inefficient.)

Yes, but gravity is the main factor here. If a QB threw the ball on the shortest path, a strait line, it would be impossible arm strength to accomplish on a 40 yard throw. Likewise a QB throwing the ball as high as a skyscraper and it traveling 40 yards in distance. The real measure is ball velocity as it leaves his hands a a tight rope tends to have greater velocity than a moon shot.

Humor me. The critical point is 45 degrees, IIRC.

Horizontal distance is 40 meters.

One QB throws the ball with an angle of 45 degrees. The other throws with a height of 75 degrees. Who has the greater velocity?

The formula for horizontal distance is:
R = [v^2 sin(2α)]/(g)
So v = sqrt [Rg/(sin[2α])]

R = 40.

α for the low arc is: 45 degrees (calculated using the same formula)

α for the high arc is: 75 degrees.

So the HORIZONTAL velocities are, respectfully: sqrt [40m *g/(sin[2*45])] = 19.8 m/s, and sqrt [40m*g/(sin[2*75])] = 39.6 m/s.

The interesting thing with sin is that it's a periodic function. That means there are times when a LOWER trajectory would take more initial velocity than a higher one, and there are times when a HIGHER trajectory would take more initial velocity. You brought up the fact that a zero trajectory would take infinite velocity. That's true. So would a 90 degree trajectory.

So, if the QB is throwing with an arc greater than 45 degrees, each additional degree of arc requires more arm strength. If the QB is throwing with an arc less than 45 degrees, each additional degree of arc REDUCTION requires more arm strength. Russell Wilson appears to throw with greater than 45 degree arc, so the higher he throws it, the more arm strength it takes.

I think that the truth of the matter here is that the biggest factor in arc is QB preference, and if there's a weakness or a strength with a QB who chooses one or the other, it has to be related to vision and anticipation, not arm strength.

It totally has a lot to do with arm strength. It takes a lot more arm strength to throw a deep out on a rope than to throw a lofted pass. All it takes is throwing a few passes to understand that. The main reason to arc a throw rather than throw a frozen rope is catchability and layering the pass through coverage. It's all about velocity vs trajectory.

Again, it depends entirely on if the angle of throw is greater than or less than 45 degrees. I feel like you didn't read or didn't understand my post.
Oct 3, 2023 at 7:41 PM
Originally posted by 5_Golden_Rings:
I had thought if he declares for the draft, he becomes ineligible to play college ball, and if he declares fro the draft and turns down the team that drafts him, he has to sit out of the NFL for an entire year. I guess he could still make endorsements with USC, but he won't be playing. Unless the rules have changed.

I think the idea would be that he doesn't actually declare for the draft technically depending on how the order shakes out and what information he learns about the plans of the teams in those slots.
Oct 3, 2023 at 7:42 PM
Originally posted by random49er:
Originally posted by Memphis9er:
Originally posted by 5_Golden_Rings:
Originally posted by 49erKing:
Originally posted by 5_Golden_Rings:
Originally posted by Giedi:
Originally posted by brodiebluebanaszak:
Originally posted by Giedi:
Originally posted by tankle104:

Arm is definitely stronger than Montana's.

No not really. They both throw extremely catchable balls on all their different types of throws though. Both elite there.

Disagree, I remember Montana's long balls had more arch to them. Early in Montana's career (Before Rice) he had long ball issues. Which are not a big deal during the early years as he had Wendell Tyler. That Aiyuk 40+ yard throw was a flatter trajectory than Montana's usual deep throws, as I recall it.
Having a lower trajectory on deep balls all the time means your arm isn't as strong, because you have to cut out the wasted motion. You think Russell Wilson has a weak arm? His deep balls are more tear drop than anyone's I've ever seen.

The second the ball leaves your hand, the only forces working on it are gravity and friction. A high arching ball travels a further net distance than a flattened one. It takes more arm to throw more distance. QBs who depend on a flat arc for deep balls probably do not have as strong an arm as those who don't.

HOWEVER, it could also merely be a preference. The QB maybe doesn't anticipate as much as the tear drop guy and has to sling it to get it there in time, or perhaps they're paranoid about the ball taking a long time to get there.

.
.
.
EDIT: before I get tarred and feathered, I'm not talking about Brock. His arm is plenty strong enough to hit every throw you need to wear a gold jacket. I'm just talking theoretically. If you HAVE to have a low trajectory to throw deep, your arm isn't as strong as someone who can easily do either.

Any science behind this? I think if someone wants to throw deep, if they have the time, and it makes sense, they "naturally" conform to throwing with a higher arc/higher trajectory. I mean that's how I feel when I play catch with the guys. If you're trying to laser it while going deep I think that actually means you have a stronger arm than most.

Yeah. Pythagoras (Extended to curves; the same principle applies, you just add up the infinitesimal distances via a line integral, but it's essentially the same thing. In Euclidean geometry, a straight line is the shortest path between two points.). A high arcing ball travels more distance. As the ball is not getting any additional force as it leaves (basic physics), what you put into it upon release is all it has. So throwing with a high arc doesn't give you some boost. That's not how physics work. Draw a free body diagram. Only gravity and friction are of any consequence once it's released.

So, the high arcing ball is thrown further in actual distance traveled than the low arcing one.

Which means, if you MUST throw with a low arc to get it there, your arm is weaker. (By arm strength I mean how far you can throw the ball, but I see no reason why velocity and distance would be different as a measure of arm strength unless the QB has mechanical problems which make one of either his distance or velocity throws more inefficient.)

.
.

EDIT: Just to be clear, however, I do believe that the most likely reason most of the time for why some QBs throw with a low arc and some don't is that the low arc guys either have poorer deep anticipation or don't trust their accuracy and timing as much, or fear that a super fast safety might catch up and make a play. In other words, I think a lot of low-arc deep ball guys COULD throw tear drops but choose not to.

Kaepernick used to throw frozen ropes, I don't think he could put air under it. It takes more strength to throw those low angle passes because you have to put more mustard on it to get the ball to go where you want it. The downside is those balls are much harder to catch. Putting air under it means you don't have to throw it as hard to get it to the target, and the balls are much easier to catch. Josh Allen is probably the best pure arm talent that can do either as needed.

I mean Force is Force,...and angles are angles. I highlighted the angle that's going to get you the furthest distance for a given (equal) force in the chart below. But by all means,...notice the matching pairs of complimentary angles as well. More arc doesn't always equal greater distance. There's a sweetspot.


In highlighting the equivalent of a fastball-type throw and saying it takes more strength,....all you're really talking about or giving "credit" for is the low angle that the thrower has changed to (see 5°-15°). You take the same "strength" that went into the throw, angle it 45°,...and you'll get exactly what you see above, which is a throw with an arc that is the furthest throw possible. Same strength,...further throw. You "feel" like it was stronger because the ball traveled faster on camera.

@ the end of the day, Force still equal mass x's acceleration,....hence,...the reason you have to simply trust a speed gun to tell you what's up,...or do what's alot easier during a football game,...which is see where the ball landed from where it was launched.

But being able to throw fast and hard at a low angle doesn't necessarily mean that that athlete has the athleticism to get you a ball of the same speed with a 45° angle throw. "Arm angles" really are everything.

Yes, the point is that when the degree of angle INCREASES when you're PAST 45 degrees, in order to get the same horizontal distance you need more initial velocity. Conversely, when the degree of angle DECREASES when you're BELOW 45 degrees, in order to get the same horizontal distance you need more initial velocity. 45 degrees is the magic inflection point.
Oct 3, 2023 at 7:47 PM
Originally posted by BOI49er:
Originally posted by DonnieDarko:
Originally posted by random49er:
It's better to just assume all the hand strengths to be "equal" or "even" to each other...to get enough of a spiral by this stage of their careers.

Then compare the real difference, which is arm strength.

But if you again want to go the way of the nerds... I remember this exerpt from an article:

"An article in the American Journal of Physics (2003) that measured the coefficient of drag of a spinning football to be around 0.05 to 0.06."

And so assuming these following things...

The air resistance is proportional to the square of the velocity of the football
The Mass of the ball is 0.42 kg.
The density of air is 1.2 kg/m3.
The coefficient of drag for the football is 0.05 to 0.14 (initial)
Typical initial speed of a thrown football is around 20 m/s

w/ all of these forces acting on the ball:


The furthest throw goes from 45 degrees to



The more you ignore drag/spin/air resistance, the closer it gets back to 45° as the furthest throw.

What if you got the wind at your back? I imagine a higher trajectory would fare better
True. With a tail wind, you would get farther launching at slightly more than 45 degrees, as the ball would be in that wind longer, given gravitational acceleration is constant. Conversely, into a headwind, you would do better launching slightly lower than 45 degrees. If your WR was moving away from you, you would also benefit from a lower trajectory as the ball would get there more quickly.

Since there is air resistance, in a no wind situation, a launch slightly above 45 degrees would help a bit as going more against gravity will lower the speed a bit as the parasite drag varies with the square of velocity. Also, you could expect some aerodynamic lift as long as the angle of attack was positive to the longitudinal axis of the ball.

Better to just go practice and see what works.
Yall start talking about friction and wind resistance and tail winds and you move outside of first and second year physics and have to start opening those big, green, ugly classical mechanics textbooks which force you to deal with impossibly annoying details.
Oct 3, 2023 at 7:49 PM
Originally posted by 5_Golden_Rings:
Yall start talking about friction and wind resistance and tail winds and you move outside of first and second year physics and have to start opening those big, green, ugly classical mechanics textbooks which force you to deal with impossibly annoying details.

We're already there!
Oct 3, 2023 at 7:51 PM
Originally posted by 49ers81:
Good news for the 49ers, bad news for everyone else in the league. From an article in the newsfeed.

"Griese and Purdy spent time talking about what it takes to develop trust so Purdy can get through his reads and get the ball out quick, trusting his pass catchers to be where they're supposed to be when they're supposed to be there and throwing with more anticipation.

Early returns suggest that Purdy has fully embraced that coaching point. He's improved his time before passing from 2.84 seconds (29th in the NFL in 2022) to 2.56 seconds (tied for sixth fastest). Despite the ball coming out faster, Purdy is pushing the ball further down the field (7.2 air yards per attempt, up 0.2 from last year) and getting bigger plays (9.1 yards per attempt, up from 8.4 last year).

What's more, a whopping 48.2% of Purdy's pass attempts have gained a first down or touchdown, the highest percentage in the league. Miami Dolphins quarterback Tua Tagovailoa is second at 47.8%, but every other quarterback is at 38.5% or below."

Scary
Oct 3, 2023 at 7:56 PM
Originally posted by NCommand:
Originally posted by GoreGoreGore:
Originally posted by SLCNiner:

Crazy what a good QB can do. He's also elevated the OL as well.

He didn't elevate it. He and Kyle made it nearly obsolete with Brock's TTT, play calling and Griese's focus on this in the off season coupled with our stellar YAC monsters winning instantly.

But at some point, they'll need to stand on their own when this formula isn't working. Then we'll know more. This weekend might be that test.

PS: That's not to take anything away from how well they've played either.

Oct 3, 2023 at 8:02 PM
Originally posted by random49er:
Originally posted by 49ers81:
Good news for the 49ers, bad news for everyone else in the league. From an article in the newsfeed.

"Griese and Purdy spent time talking about what it takes to develop trust so Purdy can get through his reads and get the ball out quick, trusting his pass catchers to be where they're supposed to be when they're supposed to be there and throwing with more anticipation.

Early returns suggest that Purdy has fully embraced that coaching point. He's improved his time before passing from 2.84 seconds (29th in the NFL in 2022) to 2.56 seconds (tied for sixth fastest). Despite the ball coming out faster, Purdy is pushing the ball further down the field (7.2 air yards per attempt, up 0.2 from last year) and getting bigger plays (9.1 yards per attempt, up from 8.4 last year).

What's more, a whopping 48.2% of Purdy's pass attempts have gained a first down or touchdown, the highest percentage in the league. Miami Dolphins quarterback Tua Tagovailoa is second at 47.8%, but every other quarterback is at 38.5% or below."

Scary

Crazy, I take a lot of tuas stats with a grain of salt because they're super skewed from that 70 point game that was a joke. We will have to see how it looks later on because it's just horribly skewed from the god awful broncos.

Purdy and the offense has been consistent all year and I think that's better. What he's done this year is just remarkable, honestly unprecedented.

it's annoying when people say any decent qb would be doing that in this offense with the play calling but when someone says that, they clearly don't understand the qb position. I'm sure QBs would be doing good here but he's executing the position at a ridiculously high level. The way he is reading defenses, anticipating, accuracy, pocket awareness, trusting his guys etc. it's more than him just going out and hitting his first read. Brock is a special player and we are in for a hell of a ride these next 10+ years
Oct 3, 2023 at 8:06 PM
Originally posted by 5_Golden_Rings:
Really hope he pulls a Brady and takes under market value.

Would be amazing. I could see him doing that if he thought it would help us compete for Super Bowls. Taking like $35M-$40M instead of $55M+. I'm not banking on it but I wouldn't be surprised - that's still a fortune and you can Tell how passionate he is about winning and being great.

like I said, I'm not banking on that, but would be super cool. Would help extend our super bowl window. If he ends up being great, like it seems he will be, our window will be huge anyways.

what's cool about him being in this situation as a young player is that it's teaching him the role and letting him grow into it, instead of him having to do everything and more as a young player. So when he does get his payday and the team isn't as talented - he should be able to help elevate the team still and be a top notch qb.
Oct 3, 2023 at 8:07 PM
Originally posted by Chance:
Originally posted by Jcool:
Originally posted by Memphis9er:
Originally posted by 5_Golden_Rings:
Originally posted by SanDiego49er:
Who is that meathead on Twitter that keeps track of Brock's "almost could have been bad plays?" What will he say this week?


Probably that he could have completed that pass to McCaffrey lmao. Or that the first deep ball wasn't perfect. But I mean ffs the guy had a 97.2 QBR. Anyone trashing him after a near perfect performance like that loses their football card.

Did you see what the PFF guys said about him? The week 4 review for the game the little bald guy was trying to say that Purdy was trying to split the safeties with the deep pass to BA and that it was fortunate that he was do bad off target on that pass or else it would've been picked off. It seems pretty obvious that he was leading Aiyuk away from the safeties and almost overthrew Brandon.

He is playing great but no one is perfect. He mad a bad throw and it worked out. Great for the 49ers.

That was not a bad throw, sorry. It was a low percentage throw insofar he let the ball go before Aiyuk fully settled in his route 45 yards downfield in tight double coverage, but the ball was put in a place only his guy could make a play. Bad throw my a*****e. Let's wait in the all-22.

Looking at it from behind the QB, it sure looks like he saw the safety's leverage and threw it away from him, which means it was quite the elite, accurate throw.
Oct 3, 2023 at 8:10 PM
Bwahahaha! Steven Ruiz just updated his silly QB rankings and has Purdy at 25. Dunning-Krueger called and want their effect back.

https://nflrankings.theringer.com/power-rankings
[ Edited by Chance on Oct 3, 2023 at 8:11 PM ]
Oct 3, 2023 at 8:16 PM
Originally posted by SmokeyJoe:
Originally posted by jonnydel:
For some reason I'm reminded of my ex wife.....

At least that thing doesn't talk.

Don't be so sure...

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