This post is based on the following question from Max S:
Question: I had a couple questions about throwing the disk. The first is about throwing in crosswind. My understanding of crosswind throwing seems to be flawed. Example: Wind is going right to left. I’m throwing a big outside-in flick, or a big inside out-backhand. (I’m a righty). By my understanding, the wind should be pushing the bottom of the disk, therefore pushing it to the left and causing it to even out. So why is it that that doesn’t always happen? Instead of evening out, the disk sometimes drops into a blade, or evens out and then overturns (I can’t remember exactly which). In addition to that, the backhand inside-out and the flick outside-in tend to have different results when thrown in the same wind. The only obvious difference i can spot between the two is the spin of the disk: for backhand it is clockwise and for flick it is counterclockwise. This leads me to believe that the spin direction of the disk has an effect on the travel path of the disk in wind. Can you confirm this? Can you also offer some advice for throwing in cross-wind? I’ve been playing ultimate for a bit, so I can throw pretty much perfectly without wind, but this lack of understanding of cross-wind patterns is dragging me down. You have a pretty good article here on down and upwind throwing, but nothing on crosswind – I hope to see one soon? Brodie Smith doesn’t have a video for crosswind either, so there isn’t much resources for learning to throw crosswind
Answer: I like how you talked through the example and got into a bit of the physics of the disc. Let me go into a bit more detail for you. On an inside-out backhand, the spin of the disc will cause it to rise (since it’s spinning upwards), whereas an outside-in disc will always be falling since the disc is spinning downwards. So, when you have a right to left wind, you will want to throw a slightly inside-out backhand or a mostly flat backhand and start it right of your target since the wind will bring it to the left. You will want a lot of spin on the disc and try to not throw it with a lot of pitch on the disc (the front of the disc higher than the back of the disc). Think of a disc like a wing so the more the nose of the disc is up, the more it will stall out. The flatter the disc is, the more smoothly it will fly.
When you throw an outside-in backhand in the right to left wind, you would think the wind would hit the top of the disc causing it to flatten out but since the disc is fighting the wind, and because it’s spinning down, it will have a tendency to turn even more in and blade, as you’ve experienced.
As you mentioned, you see a difference in a backhand IO and a flick OI…that’s because of what I talked about above…the IO you throw low and it spins high; the OI you throw high and it spins low.
In a crosswind, I try to use the wind as much as possible. That’s why I find throwing it straight and flat or throwing a backhand IO works the best.
Ultimately the best way to learn the physics of a disc in flight is to throw different kinds of discs (only throwing ultimate discs will actually hinder your throwing – if you get into throwing golf disc and dog discs, your throwing will improve exponentially). Thank you for this question – I know one of the most fundamental things I ever learned was in my first year of playing – a guy taught me about the edges and the difference between an IO and an OI and how I wanted to throw the disc with an edge and have it end up flat ideally. Pretty eye opening at the time.