Winning Fathier races in Star Wars Outlaws is just one of the many ways you can make a truckload of credits without doing much work. After all, you're not racing yourself, you're just making a bet and watching your credits multiply. But how do you know who the winner will be?
Since Fathier racing and betting is rooted in Star Wars' criminal underworld, a lot of the races are rigged. If you can track down the race tip for yourself, you can bet on the winning Fathier and benefit too. The first Fathier race you can win is very early in the game while you're on Canto Bight, but you'll find more tips and betting tables across the galaxy.
The first time you encounter a race tip is when you meet Valek while still on Canto Bight. He's too busy to go and place a bet, but he gives you a race tip so you can place one for him, even though you're clearly going to steal it for yourself. All Fathier race tips are randomised, so when you read the datapad next to him, it'll say something different for you than it did for me.
Generally, it gives you a description by which to recognise who the winner is, whether it's their name, or a defining feature such as their sex, height, weight, or planet of origin. The feature in question will be bolded. For example, my tip read:
Most important thing: Make a note of what the tip was. For some reason the game doesn't seem to record this info anywhere and the datapad will disappear when you return.
Once you have Valek's tip, head back to the Broken Hoof cantina where the game began and activate the betting table on the left near the entrance. If you've forgotten the tip, a box in the top right will at least tell you what the tip was related to, even if it doesn't tell you the tip itself.
Look at each Fathier, pick the one that fits your tip, and make sure you bet the largest amount possible to maximise your winnings. The info in the detail section is represented like this:
Use these to choose the correct Fathier from the tip and victory—plus some credits—will be yours.
You can find more Fathier tip datapads in certain locations, but generally they seem to be located in Syndicate vaults, such as the Pyke Syndicate Vault in their Mirogana district or the Crimson Dawn Vault in theirs. The strange thing is that new tips seem to periodically respawn in these vault locations, though I'm not 100% sure what the trigger for this is beyond just returning after some time has passed.
Another source is through specific characters. If you return to the Fathier betting table in Mirogana enough, you'll meet a disgruntled ex-jockey called Morin Bryte, who'll offer to give you a race tip if you pay him some creds, and this one will actually be listed as proper intel, too. When you bet using this intel, you can get a reminder of the exact info.