# Please explain to me the physics that allows this weird field goal to happen **URL:** \ **Category:** Factual Questions\ **Created:** [November 11, 2014, 10:51am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327 "2014-11-11T10:51:10Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [November 11, 2014, 7:05pm UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/21 "2014-11-11T19:05:46Z")
[Here’s a better video](http://www.49ers.com/video/videos/Dawson_35yard_Gamewinning_Field_Goal/79e860db-3704-4343-867b-758281bd6f6b) of it. The hook doesn’t look nearly as dramatic there. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [November 11, 2014, 7:14pm UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/22 "2014-11-11T19:14:04Z")
> [@Pasta](#): > > The point is that the ball’s either in the net already and/or it skimmed the crossbar (very possible from that camera angle) before it appears to curve. Again, not sure what you are watching but the ball is no where near the crossbar nor the net during the interesting part of the travel. All that takes place well before it reaches the goalposts. But also, the movement of the ball is really not that dramatic. His kicks apparently always curve right so he knows to kick left and let the normal movement of the ball take it through the uprights. ---
**Author:** ![Your\_Great\_Darsh\_Face](https://avatars.discourse-cdn.com/v4/letter/y/ac8455/32.png) [@Your\_Great\_Darsh\_Face](https://boards.straightdope.com/u/Your_Great_Darsh_Face)\ **Post date:** [November 11, 2014, 7:48pm UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/23 "2014-11-11T19:48:32Z")
It’s unusual for me to see a right-footed kicker slice right - most of the place-kickers I’ve seen in Rugby or soccer hook left if they’re right-footed. Rarely, a Rugby team will have a secondary kicker take a kick that’s well out towards the “wrong” touchline for their regular kicker, if they have the luxury of an opposite-footed kicker (Conor O’Shea took the odd one for Ireland in his day for this reason, and I remember being amused to hear the commentator explain that this was because “he’s a left-footer”). “left-footer” is a derogatory term for a Roman Catholic and not something you’d normally say when you’re talking about Irishmen lest ill come of it. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 11, 2014, 8:04pm UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/24 "2014-11-11T20:04:14Z")
> [@](#): > > Again, not sure what you are watching but the ball is no where near the crossbar nor the net during the interesting part of the travel. All that takes place well before it reaches the goalposts. Do you have a side view that you’d like to share? If not, how can you tell? ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [November 11, 2014, 9:28pm UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/25 "2014-11-11T21:28:46Z")
> [@Chronos](#): > > Do you have a side view that you’d like to share? If not, how can you tell? Because the netting is only a short distance beyond the uprights. The ball is kicked from the 25 yard line so it goes through the uprights at 35 yards, and hits the netting roughly 5 yards later. It’s obvious when it hits the nets, the ball stops its flight and drops down. All the curving of the ball is done in the first half of the flight, well before it reaches the goalposts. There’s just no room for any change in direction after it passes through the goalposts. The netting is too close. ---
**Author:** ![CurtC](https://avatars.discourse-cdn.com/v4/letter/c/ce73a5/32.png) [@CurtC](https://boards.straightdope.com/u/CurtC)\ **Post date:** [November 11, 2014, 9:47pm UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/26 "2014-11-11T21:47:10Z")
> [@Chronos](#): > > Do you have a side view that you’d like to share? If not, how can you tell? I have this suspicion that we’re being whooshed here, but here goes… In [this video](http://www.49ers.com/video/videos/Dawson_35yard_Gamewinning_Field_Goal/79e860db-3704-4343-867b-758281bd6f6b) at the 12-second point he kicks it, and you can immediately see it pass just left of the hand of one of the defenders. It’s traveled 7 yards at this point. At 13 seconds, the ball, from the camera’s POV, has passed above the level of the crossbar. I would estimate that the ball is somewhere between the 15-yard and 10-yard lines there, and it still has another 20 to 25 yards to go before it passes the plane of the goal posts. But from that point on, it stays well within the crossbars from the camera’s POV. All of this interesting stuff we’re talking about happens while the football is within the goal posts from the camera’s perspective. You can also tell from the proportion of time it’s in the air - the ball travels 35 yards horizontally before it passes the goal posts, then travels another 10 or so before it hits the net behind them. By the time it gets 1/4 to 1/3 the way into its travel, you can see that the curve has started, so this is well short of being even halfway to the goal posts. Apologies if I’m being whooshed. ---
**Author:** ![Pasta](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@Pasta](https://boards.straightdope.com/u/Pasta)\ **Post date:** [November 11, 2014, 10:17pm UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/27 "2014-11-11T22:17:14Z")
> [@CurtC](#): > > In [this video](http://www.49ers.com/video/videos/Dawson_35yard_Gamewinning_Field_Goal/79e860db-3704-4343-867b-758281bd6f6b) at the 12-second point he kicks it, and you can immediately see it pass just left of the hand of one of the defenders. It’s traveled 7 yards at this point. At 13 seconds, the ball, from the camera’s POV, has passed above the level of the crossbar. I would estimate that the ball is somewhere between the 15-yard and 10-yard lines there, and it still has another 20 to 25 yards to go before it passes the plane of the goal posts. But from that point on, it stays well within the crossbars from the camera’s POV. All of this interesting stuff we’re talking about happens while the football is within the goal posts from the camera’s perspective. > > You can also tell from the proportion of time it’s in the air - the ball travels 35 yards horizontally before it passes the goal posts, then travels another 10 or so before it hits the net behind them. By the time it gets 1/4 to 1/3 the way into its travel, you can see that the curve has started, so this is well short of being even halfway to the goal posts. After a closer examination of the clip, I’m convinced that the curving happens in the air. ---
**Author:** ![SlackerInc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slackerinc/32/275_2.png) [@SlackerInc](https://boards.straightdope.com/u/SlackerInc)\ **Post date:** [November 12, 2014, 12:13am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/28 "2014-11-12T00:13:26Z")
> [@Jackknifed\_Juggernaut](#): > > I’m with the OP. I’ve watched a LOT of football and the only time I’ve seen a place kick move that much is on extremely windy days. Since this was in a dome with presumably no wind, it was quite extraordinary. Thanks, glad to hear I wasn’t the only one flummoxed. I wonder if you have to watch a lot of football to realize how weird that kick was? I play tennis, and serious curving with a heavy topspin shot is de rigueur. But I feel like the ratio of spin RPMs to mass to velocity and all that\* is a lot different between the sports. Plus, as I say, I just see so many kicks and never see them do that. * * * \*I was the best physics student in my 400-plus high school class at a well above-average Minnesota high school, but I did not pursue it in college and I know there are lots of people here who are legit experts–so please forgive the hackery. ---
**Author:** ![sisu](https://avatars.discourse-cdn.com/v4/letter/s/df705f/32.png) [@sisu](https://boards.straightdope.com/u/sisu)\ **Post date:** [November 12, 2014, 12:17am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/29 "2014-11-12T00:17:36Z")
> [@polar\_bear](#): > > As someone who watches “soccer”, that spin was nothing special. If it more difficult to get this effect with an american football is something I can’t comment on, but with a regular round ball this type of spin is as common as it gets. I agree its harder with an egg shaped ball but we see it in the AFL when people execute a banana kick, although we drop the ball and the angle is more acute. The punter kicked the ball to induce spin so it moved, also could have been wind assisted. [https://www.youtube.com/watch?v=-HhQfaLrD6w](https://www.youtube.com/watch?v=-HhQfaLrD6w) ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [November 12, 2014, 12:18am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/30 "2014-11-12T00:18:41Z")
> [@SlackerInc](#): > > … > I have watched more FG attempts than the vast majority of people, I’d have to think. For ten years, I watched four games every week. Then I got NFL Sunday Ticket and spent a few years using multiple TVs to watch games at the same time, plus flipping around to ones that were tight or if a team was driving past midfield. Now for the past few years I’ve had NFL Rewind and I watch the majority of games in their entirety, in a condensed version (takes about 30 min.) that shows every play… Wow. I can’t be the only one who’s impressed. ---
**Author:** ![SlackerInc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slackerinc/32/275_2.png) [@SlackerInc](https://boards.straightdope.com/u/SlackerInc)\ **Post date:** [November 12, 2014, 12:52am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/31 "2014-11-12T00:52:03Z")
Thanks, \*\*Leo \*\*(assuming that’s not snark). **Sisu** , the AFL “banana kick” video was interesting, thanks for linking that. Watching that, though, helped me think about one of the key ways I feel like the 49ers kick was so weird, although I’m still not able to articulate, physics-wise, what the weirdness is. With these banana kicks, and in many past NFL FG attempts that I’ve seen “hook”, the curve is almost all to the left (or sometimes right) of an imaginary plane that extends out perpendicularly from the front of the kicker’s body. That is, the ball starts out going in the direction they are facing, then tails off in a curve. Whereas in this case, the ball went over a significant amount to the left of where the kicker was, then moved sharply to the right–and it wasn’t a continuous curve, either, or certainly didn’t appear to be. So after the announcer says “Dawson hooks it home”, the color commentator responds, chuckling: “It was a hook, \*then \*a slice! But it’s three points, and it’s the game winner for Dawson.” And going back to tennis (I don’t play golf, but the principle seems the same), how can you have topspin, then slice in the same shot? BTW, if you have an actual NFL Rewind subscription (and you can get a free trial sub that lasts a few hours, I think), you can also see a slo-mo replay of the kick from a different angle; not sure if it’s possible to access that in the way someone did linking the “live” angle here. ---
**Author:** ![Asimovian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asimovian/32/172_2.png) [@Asimovian](https://boards.straightdope.com/u/Asimovian)\ **Post date:** [November 12, 2014, 1:01am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/32 "2014-11-12T01:01:28Z")
> [@SlackerInc](#): > > Whereas in this case, the ball went over a significant amount to the left of where the kicker was, then moved sharply to the right–and it wasn’t a continuous curve, either, or certainly didn’t appear to be. So after the announcer says “Dawson hooks it home”, the color commentator responds, chuckling: “It was a hook, \*then \*a slice! But it’s three points, and it’s the game winner for Dawson.” And going back to tennis (I don’t play golf, but the principle seems the same), how can you have topspin, then slice in the same shot? Again, I don’t believe there was ever any actual hook. He kicked the ball “straight” to the left — it didn’t hook that direction. The only actual curve involved was the “slice” to the right. ---
**Author:** ![SlackerInc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slackerinc/32/275_2.png) [@SlackerInc](https://boards.straightdope.com/u/SlackerInc)\ **Post date:** [November 12, 2014, 1:08am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/33 "2014-11-12T01:08:51Z")
Maybe so, but this is just not what you normally see (in particular, you don’t see a right-footed kicker’s kick move at a leftward angle and then significantly back to the right). And I can understand why someone upthread thought it might have hit the crossbar or net to cause the shift (though I agree that’s not the case): instead of curving relatively continuously, the ball appears to really almost \*jerk \*to the right at one point. I suppose this must be some kind of optical illusion (though maybe their heating system has a vent that is poorly designed to blast right in that direction?), but it also shows up in the slo-mo reply from a different angle. ---
**Author:** ![Pasta](https://avatars.discourse-cdn.com/v4/letter/p/ecccb3/32.png) [@Pasta](https://boards.straightdope.com/u/Pasta)\ **Post date:** [November 12, 2014, 1:13am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/34 "2014-11-12T01:13:43Z")
> [@SlackerInc](#): > > And I can understand why someone upthread thought it might have hit the crossbar or net to cause the shift (though I agree that’s not the case) Indeed. I have watched a lot of football, and my brain just immediately locked on to seeing the behavior as physical contact with something. It was just too odd a trajectory. But upon repeated replay and judicious pausing, I couldn’t make the story stick. > [@](#): > > but it also shows up in the slo-mo reply from a different angle. Do you have a link to this? ---
**Author:** ![SlackerInc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slackerinc/32/275_2.png) [@SlackerInc](https://boards.straightdope.com/u/SlackerInc)\ **Post date:** [November 12, 2014, 1:25am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/35 "2014-11-12T01:25:05Z")
All I can come up with is a link to their offer for a 7-day free trial. Once you’ve got that, you would just select the 49ers game, go to the very end (of the non-condensed version), and you can watch and rewind etc. to your heart’s content: [https://gamerewind.nfl.com/nflgr/secure/packages?ttv=0](https://gamerewind.nfl.com/nflgr/secure/packages?ttv=0) ---
**Author:** ![Cugel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cugel/32/1199_2.png) [@Cugel](https://boards.straightdope.com/u/Cugel)\ **Post date:** [November 12, 2014, 2:26am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/36 "2014-11-12T02:26:27Z")
Here’s a bit of Johnathan Thurston’s work with the curving “rugby” ball (he plays league) [![]( " - YouTube") ](https://www.youtube.com/watch?v=KErGs1pejmM) ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [November 12, 2014, 2:41am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/37 "2014-11-12T02:41:21Z")
[QUOTE=SlackerInc;17892792: instead of curving relatively continuously, the ball appears to really almost \*jerk \*to the right at one point. I suppose this must be some kind of optical illusion (though maybe their heating system has a vent that is poorly designed to blast right in that direction?), but it also shows up in the slo-mo reply from a different angle.[/QUOTE] In soccer, it really is a real jerk (jerk = rate of change of acceleration): the ball sharply starts decelerating and simultanously sharply starts accelerating in the side direction ( and/or the down direction). ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [November 12, 2014, 2:51am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/38 "2014-11-12T02:51:34Z")
It occurred in New Orleans. “Kick me something, mister!” So, he did. ---
**Author:** ![SlackerInc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/slackerinc/32/275_2.png) [@SlackerInc](https://boards.straightdope.com/u/SlackerInc)\ **Post date:** [November 12, 2014, 4:06am UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/39 "2014-11-12T04:06:04Z")
I’m clearly missing a cultural reference of some sort there. **Cugel** , cool video. Looks like it’s clearly of benefit to hook the ball in that sport. But contra Melbourne’s point, those curves still look fairly continuous. They also seem to really consistently be a “hook” (toward the opposite direction as the kicker’s dominant foot, so usually to the left although presumably a lefty would have it hook to the right), whereas the 49ers kick goes left, then hard right. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [November 12, 2014, 12:39pm UTC](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327/40 "2014-11-12T12:39:24Z")
I can’t be bothered to register to look at **SlackerInc** ’s link, but from the [video at 49ers.com](http://www.49ers.com/video/videos/Dawson_35yard_Gamewinning_Field_Goal/79e860db-3704-4343-867b-758281bd6f6b), it does look like the ball might first hit the net just a little to the right of center, then bounce further to the right before falling. Maybe someone who did can see if that’s possible. [Previous page](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327.md?page=1) [Next page](https://boards.straightdope.com/t/please-explain-to-me-the-physics-that-allows-this-weird-field-goal-to-happen/704327.md?page=3)