I have a weird shaped head, its round but not. The oval hats don't fit either. Any hat preshaped, out of the box, I try to wear looks like I put it on sideways.
My good felt I keep for shows is custom made, you should see the shape of the form that stays in the hat when it's not being worn..lol... I think my mom dropped me on my head a few times as baby..
Anyhow, my point is fit has a lot to do with it staying on. Also one thing I was doing was buying a hat too small to mush down on my head. I used Bobby pins, stampede strings, double sided tape, hairspray, it doesn't work!
If a hat fits well it will be snug but not tight or give you headaches after wearing a short time.
I was trying to cramp my head and hair into a 6 7/8 but after getting a hat fitted I really wear 7 1/8. It made the difference in wearing a hat all long in the wind or at a high lope without stampede strings. Admittedly if the wind is going to be blowing hard(25mph+), I wear a ball cap as I hate the feeling of the wing tugging on my hat. It makes me cranky.
I like the American straws. I have one I have been wearing for several summers now for show and work. All my hats have a 5" brim and I have no issues with keeping it on and I love the vented tops. It feels so good on a hot day when your head is sweating a bit, you strike a trot to create a little breeze over the top of your head-air conditioning!
I'm not saying you need to go out and buy a custom hat but I'd get your head measured and get a hat that fits.
This is the straw I have. Note the ventilation.
I DON'T LEAD 'EM AND FEED 'EM, I RIDE 'EM AND SLIDE 'EM.
PLAYBOYS OKIE CODY "HOOEY" 10/21/2019