Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This Jax build has served me well, as well as anyone that's decided to try out Jax. Its main focus is to get his dodge ability really high as to deny the enemy DPS champions. So this build is more recommended for enemy teams with more Ad then AP. Using your leap strike will allow easy access to fleeing enemies, coupled with the speed from the trinity force and the extra damage from the trinity force's passive allow easy kills for even the most novice of Jax players. The attack speed may seem low but with rage blade and Jax's passive it makes fro a great speed, additionally the black cleaver can be switched for a phantom dancer. (It may not give dodge anymore, but move speed and attack speed are great) Have fun.