Is there any trick to getting the sneak attack materia

From what I can tell, the only way to get the Sneak Attack materia is to win it as a prize in in A- and S-rank chocobo races. However, it never seems to show up as a prize for me, and when it does you can bet it isn't among the ones I win.

Is there any way to increase the odds of getting this materia? Alternately is there any place other than the Chocobo Races where you can find it?

I think the chances of getting the Sneak Materia from a win are around 1 in 60. So keep playing your odds.

Also, read somewhere that equipping your racer with the Precious Watch may boost your chances of winning it.

There is no other place where you can obtain it. Good luck!