For years shooting sports I've always had my bodies set to record to both cards simultaneously. Reasoning has been an insurance policy to cover if a card fails in some manner.
For those who shoot sports, what are your recoding preferences?
I shoot to one card. I do not shoot professionally and shoot with 2 (or sometimes 3) cameras. Never had card issues. If I would have them, there is no real harm since I do not do it professionally and in case a card in one of the camera fails, in most cases I still have some coverage from the other camera.
Investing in good high quality cards would be the starting point. Shooting in both the cards will give you piece of mind for sure, but if you are doing that on 2/3 bodies then that lot of duplication. I personally shoot one card and overflow to another.
If the body in my hand has two slots for cards then they are populated. Since the cards are present, simultaneous recording provides a backup which is insurance for any potential failure. When you are shooting for a client, backups become an important aspect, JMTC
I dont shoot backups usually. I use the second card as overflow or sometimes I use it to copy my protected files if I am trying to transfer something quickly, not during a break like half-time, ect... I also stopped shooting raw during games and only shoot jpgs. I don't end up doing anything with the raw files anyway so its a waste of space and time for me personally.